diff --git a/games/doom/factory.lua b/games/doom/factory.lua
index 6e4745a88..c20822a92 100644
--- a/games/doom/factory.lua
+++ b/games/doom/factory.lua
@@ -9577,8 +9577,8 @@ function DOOM.factory_setup()
         error("Prefab not a multiple of four: " .. tostring(P.name))
       end
 
-      P.long = math.round(f_long / 4)
-      P.deep = math.round(f_deep / 4)
+      P.long = math.floor(f_long / 4)
+      P.deep = math.floor(f_deep / 4)
     else
       error("Unsupported scale " .. tostring(P.scale) .. " in prefab: " .. tostring(P.name))
     end
diff --git a/games/doom/x_doom1.lua b/games/doom/x_doom1.lua
index f9890faf5..b6ecea8a7 100644
--- a/games/doom/x_doom1.lua
+++ b/games/doom/x_doom1.lua
@@ -10595,8 +10595,8 @@ function ULTDOOM.factory_setup()
         error("Prefab not a multiple of four: " .. tostring(P.name))
       end
 
-      P.long = math.round(f_long / 4)
-      P.deep = math.round(f_deep / 4)
+      P.long = math.floor(f_long / 4)
+      P.deep = math.floor(f_deep / 4)
     else
       error("Unsupported scale " .. tostring(P.scale) .. " in prefab: " .. tostring(P.name))
     end
diff --git a/games/heretic/factory.lua b/games/heretic/factory.lua
index 9cc6e6833..bfcaae459 100644
--- a/games/heretic/factory.lua
+++ b/games/heretic/factory.lua
@@ -6004,8 +6004,8 @@ function HERETIC.factory_setup()
         error("Prefab not a multiple of four: " .. tostring(P.name))
       end
 
-      P.long = math.round(f_long / 4)
-      P.deep = math.round(f_deep / 4)
+      P.long = math.floor(f_long / 4)
+      P.deep = math.floor(f_deep / 4)
     else
       error("Unsupported scale " .. tostring(P.scale) .. " in prefab: " .. tostring(P.name))
     end
diff --git a/games/noah/factory.lua b/games/noah/factory.lua
index 9b5df0290..7aadcf0ea 100644
--- a/games/noah/factory.lua
+++ b/games/noah/factory.lua
@@ -5171,7 +5171,7 @@ function NOAH.get_factory_levels(episode)
         end
       end
   
-      ob_size = math.clamp(low, math.round(rand.irange(low, high) * result_skew), high)
+      ob_size = math.clamp(low, math.floor(rand.irange(low, high) * result_skew), high)
       goto foundsize
     end
   
@@ -5209,7 +5209,7 @@ function NOAH.get_factory_levels(episode)
       local def_large = PARAM.float_level_upper_bound_wolf_3d - def_small or 42
   
       -- this basically ramps up
-      ob_size = math.round(def_small + along * def_large)
+      ob_size = math.floor(def_small + along * def_large)
     end
 
     ::foundsize::
@@ -5364,8 +5364,8 @@ function NOAH.factory_setup()
         error("Prefab not a multiple of four: " .. tostring(P.name))
       end
 
-      P.long = math.round(f_long / 4)
-      P.deep = math.round(f_deep / 4)
+      P.long = math.floor(f_long / 4)
+      P.deep = math.floor(f_deep / 4)
     else
       error("Unsupported scale " .. tostring(P.scale) .. " in prefab: " .. tostring(P.name))
     end
diff --git a/games/obc/factory.lua b/games/obc/factory.lua
index 28704d7aa..35a473a26 100644
--- a/games/obc/factory.lua
+++ b/games/obc/factory.lua
@@ -5128,7 +5128,7 @@ function OBC.get_factory_levels(episode)
         end
       end
   
-      ob_size = math.clamp(low, math.round(rand.irange(low, high) * result_skew), high)
+      ob_size = math.clamp(low, math.floor(rand.irange(low, high) * result_skew), high)
       goto foundsize
     end
   
@@ -5166,7 +5166,7 @@ function OBC.get_factory_levels(episode)
       local def_large = PARAM.float_level_upper_bound_wolf_3d - def_small or 42
   
       -- this basically ramps up
-      ob_size = math.round(def_small + along * def_large)
+      ob_size = math.floor(def_small + along * def_large)
     end
 
     ::foundsize::
@@ -5321,8 +5321,8 @@ function OBC.factory_setup()
         error("Prefab not a multiple of four: " .. tostring(P.name))
       end
 
-      P.long = math.round(f_long / 4)
-      P.deep = math.round(f_deep / 4)
+      P.long = math.floor(f_long / 4)
+      P.deep = math.floor(f_deep / 4)
     else
       error("Unsupported scale " .. tostring(P.scale) .. " in prefab: " .. tostring(P.name))
     end
diff --git a/games/wolf/factory.lua b/games/wolf/factory.lua
index a697dd3ff..8e0c4a5e6 100644
--- a/games/wolf/factory.lua
+++ b/games/wolf/factory.lua
@@ -5580,7 +5580,7 @@ function WOLF.get_factory_levels(episode)
         end
       end
   
-      ob_size = math.clamp(low, math.round(rand.irange(low, high) * result_skew), high)
+      ob_size = math.clamp(low, math.floor(rand.irange(low, high) * result_skew), high)
       goto foundsize
     end
   
@@ -5618,7 +5618,7 @@ function WOLF.get_factory_levels(episode)
       local def_large = PARAM.float_level_upper_bound_wolf_3d - def_small or 42
   
       -- this basically ramps up
-      ob_size = math.round(def_small + along * def_large)
+      ob_size = math.floor(def_small + along * def_large)
     end
 
     ::foundsize::
@@ -5773,8 +5773,8 @@ function WOLF.factory_setup()
         error("Prefab not a multiple of four: " .. tostring(P.name))
       end
 
-      P.long = math.round(f_long / 4)
-      P.deep = math.round(f_deep / 4)
+      P.long = math.floor(f_long / 4)
+      P.deep = math.floor(f_deep / 4)
     else
       error("Unsupported scale " .. tostring(P.scale) .. " in prefab: " .. tostring(P.name))
     end
diff --git a/games/wolf/x_spear.lua b/games/wolf/x_spear.lua
index 3429c0278..513600947 100644
--- a/games/wolf/x_spear.lua
+++ b/games/wolf/x_spear.lua
@@ -306,7 +306,7 @@ function SPEAR.get_factory_levels(episode)
         end
       end
   
-      ob_size = math.clamp(low, math.round(rand.irange(low, high) * result_skew), high)
+      ob_size = math.clamp(low, math.floor(rand.irange(low, high) * result_skew), high)
       goto foundsize
     end
   
@@ -344,7 +344,7 @@ function SPEAR.get_factory_levels(episode)
       local def_large = PARAM.float_level_upper_bound_wolf_3d - def_small or 42
   
       -- this basically ramps up
-      ob_size = math.round(def_small + along * def_large)
+      ob_size = math.floor(def_small + along * def_large)
     end
 
     ::foundsize::
diff --git a/modules/export_map.lua b/modules/export_map.lua
index 73f31d542..4a7b0f194 100644
--- a/modules/export_map.lua
+++ b/modules/export_map.lua
@@ -136,7 +136,7 @@ function EXPORT_MAP.add_entity(ent, model)
   end
 
   if origin then
-    export_printf("\"origin\" \"%d %d %d\"\n", math.round(origin.x) or 0, math.round(origin.y) or 0, math.round(origin.z) or 0)
+    export_printf("\"origin\" \"%d %d %d\"\n", math.floor(origin.x) or 0, math.floor(origin.y) or 0, math.floor(origin.z) or 0)
   end
 
   if light then
diff --git a/modules/modded_game_extras.lua b/modules/modded_game_extras.lua
index b70ac1773..83f2c7edd 100644
--- a/modules/modded_game_extras.lua
+++ b/modules/modded_game_extras.lua
@@ -1680,7 +1680,7 @@ function MODDED_GAME_EXTRAS.create_hn_info(self, LEVEL)
     end
 
     if R.lev_along and not R.is_start and #LEVEL.rooms > 2 then
-      goal_string = goal_string .. " (" .. math.round(R.lev_along * 100) .. "%%)"
+      goal_string = goal_string .. " (" .. math.floor(R.lev_along * 100) .. "%%)"
     end      
 
     return goal_string
@@ -2028,7 +2028,7 @@ function MODDED_GAME_EXTRAS.generate_hn_decorate()
     local thing_chunk = MODDED_GAME_EXTRAS.HELLSCAPE_NAVIGATOR_TEMPLATE.COPIES
     thing_chunk = string.gsub(thing_chunk, "NUMNUMNUM", editor_num)
     thing_chunk = string.gsub(thing_chunk, "NAMENAMENAME", name)
-    thing_chunk = string.gsub(thing_chunk, "SIZESIZESIZE", math.round(radius))
+    thing_chunk = string.gsub(thing_chunk, "SIZESIZESIZE", math.floor(radius))
 
     decorate_string = decorate_string .. thing_chunk
   end
diff --git a/modules/procedural_gotcha_zdoom.lua b/modules/procedural_gotcha_zdoom.lua
index f2c7f6e39..0736f2832 100644
--- a/modules/procedural_gotcha_zdoom.lua
+++ b/modules/procedural_gotcha_zdoom.lua
@@ -1429,7 +1429,7 @@ function PROCEDURAL_GOTCHA_FINE_TUNE_ZDOOM.grab_random_trait(btype, etraits)
         if einfo == info.name then
           stack = stack + 1
         if PARAM.boss_gen_tmult < 0 then
-          tprob = math.round(tprob * 0.25)
+          tprob = math.floor(tprob * 0.25)
         elseif PARAM.boss_gen_tmult > 1 then
           tprob = tprob * 2
         end
@@ -1632,7 +1632,7 @@ function PROCEDURAL_GOTCHA_FINE_TUNE_ZDOOM.all_done()
       else mult=1.0 end
     end
 
-    hpcalc = math.round(rand.pick({5000,5200,5400,5600,5800,6000})*mult*PARAM.float_boss_gen_mult)
+    hpcalc = math.floor(rand.pick({5000,5200,5400,5600,5800,6000})*mult*PARAM.float_boss_gen_mult)
 
     if batk == "hitscan" and PARAM.boss_gen_dmult<3.0 then hpcalc = hpcalc*0.75 end
 
@@ -1640,7 +1640,7 @@ function PROCEDURAL_GOTCHA_FINE_TUNE_ZDOOM.all_done()
 
     local sumcalc
 
-    sumcalc = math.round(rand.pick({400,450,500,550,600})*PARAM.boss_gen_rmult)
+    sumcalc = math.floor(rand.pick({400,450,500,550,600})*PARAM.boss_gen_rmult)
     bsummon = PROCEDURAL_GOTCHA_FINE_TUNE_ZDOOM.syntaxize(bsummon,sumcalc)
 
   end
diff --git a/modules/zdoom_otex.lua b/modules/zdoom_otex.lua
index 509b864a3..d02570f21 100644
--- a/modules/zdoom_otex.lua
+++ b/modules/zdoom_otex.lua
@@ -805,12 +805,12 @@ function OTEX_PROC_MODULE.synthesize_procedural_themes()
   end
   local scenic_fence_tab = table.copy(OTEX_SPECIAL_RESOURCES.rail_scenic_fences)
   for fence,prob in pairs(scenic_fence_tab.tech) do
-    GAME.THEMES.tech.scenic_fences[fence] = math.round(prob * 0.75)
-    GAME.THEMES.urban.scenic_fences[fence] = math.round(prob * 0.75)
+    GAME.THEMES.tech.scenic_fences[fence] = math.floor(prob * 0.75)
+    GAME.THEMES.urban.scenic_fences[fence] = math.floor(prob * 0.75)
   end
   for fence,prob in pairs(scenic_fence_tab.gothic) do
-    GAME.THEMES.hell.scenic_fences[fence] = math.round(prob * 0.75)
-    GAME.THEMES.urban.scenic_fences[fence] = math.round(prob * 0.75)
+    GAME.THEMES.hell.scenic_fences[fence] = math.floor(prob * 0.75)
+    GAME.THEMES.urban.scenic_fences[fence] = math.floor(prob * 0.75)
   end
 
   -- create liquid attachments
diff --git a/scripts/094/builder.lua b/scripts/094/builder.lua
index e9d356b07..a0dd03cf7 100644
--- a/scripts/094/builder.lua
+++ b/scripts/094/builder.lua
@@ -379,8 +379,8 @@ function B_prefab(c, fab,skin,parm, model,combo, x,y, dir,mirror_x,mirror_y)
 
     tx, ty = mid_x + tx, mid_y + ty
 
-    local bx = x + math.round(tx / 64)
-    local by = y + math.round(ty / 64)
+    local bx = x + math.floor(tx / 64)
+    local by = y + math.floor(ty / 64)
 
     local dx = (tx % 64) - 32
     local dy = (ty % 64) - 32
@@ -996,8 +996,8 @@ function B_vista(src,dest, x1,y1, x2,y2, side, b_combo,kind)
     local sp_min = 2.0 + deep / 6.0
     local sp_max = 2.0 + deep / 2.5
 
-    local front_pillars = math.round( rand.range(fp_min, fp_max) + rand.skew()*0.5 )
-    local  side_pillars = math.round( rand.range(sp_min, sp_max) + rand.skew()*0.5 )
+    local front_pillars = math.floor( rand.range(fp_min, fp_max) + rand.skew()*0.5 )
+    local  side_pillars = math.floor( rand.range(sp_min, sp_max) + rand.skew()*0.5 )
 
     gui.debugf("VISTA %dx%d --> PILLARS front:%d side:%d\n", long, deep,
                front_pillars, side_pillars)
@@ -1005,8 +1005,8 @@ function B_vista(src,dest, x1,y1, x2,y2, side, b_combo,kind)
     for fp = 1, front_pillars do
       local u = (fp - 1) / (front_pillars - 1)
 
-      local x = math.round(px1 + (px2-px1) * u)
-      local y = math.round(py1 + (py2-py1) * u)
+      local x = math.floor(px1 + (px2-px1) * u)
+      local y = math.floor(py1 + (py2-py1) * u)
       
       frag_fill(src, x,y, x,y, { solid=support })
     end
@@ -1014,13 +1014,13 @@ function B_vista(src,dest, x1,y1, x2,y2, side, b_combo,kind)
     for sp = 1, side_pillars do
       local u = (sp - 1) / (side_pillars - 1)
 
-      local x1 = math.round(px1 + (wx1-px1) * u)
-      local y1 = math.round(py1 + (wy1-py1) * u)
+      local x1 = math.floor(px1 + (wx1-px1) * u)
+      local y1 = math.floor(py1 + (wy1-py1) * u)
       
       frag_fill(src, x1,y1, x1,y1, { solid=support })
       
-      local x2 = math.round(px2 + (wx2-px2) * u)
-      local y2 = math.round(py2 + (wy2-py2) * u)
+      local x2 = math.floor(px2 + (wx2-px2) * u)
+      local y2 = math.floor(py2 + (wy2-py2) * u)
 
       frag_fill(src, x2,y2, x2,y2, { solid=support })
     end
@@ -1255,8 +1255,8 @@ function make_chunks()
     local L, M, R
 
     if q_pos then
-      M = math.round((total+2) / 3)
-      L = math.round(total / 3)
+      M = math.floor((total+2) / 3)
+      L = math.floor(total / 3)
       R = total - M - L
 
           if q_pos == 1 then return M, L, R
@@ -1350,9 +1350,9 @@ function make_chunks()
     local pos
 
         if link.where == -2 then pos = 0
-    elseif link.where == -1 then pos = math.round((diff+2)/4)
-    elseif link.where ==  0 then pos = math.round(diff / 2)
-    elseif link.where ==  1 then pos = diff - math.round((diff+2)/4)
+    elseif link.where == -1 then pos = math.floor((diff+2)/4)
+    elseif link.where ==  0 then pos = math.floor(diff / 2)
+    elseif link.where ==  1 then pos = diff - math.floor((diff+2)/4)
     elseif link.where ==  2 then pos = diff
     else
       error("Bad where value: " .. tostring(link.where))
@@ -1450,8 +1450,8 @@ function make_chunks()
       if (d_pos < d_min) then d_pos = d_min end
       if (d_pos > d_max) then d_pos = d_max end
 
-      local j1 = math.round((d_pos - 1) / JW)
-      local j2 = math.round((d_pos - 1 + link.long-1) / JW)
+      local j1 = math.floor((d_pos - 1) / JW)
+      local j2 = math.floor((d_pos - 1 + link.long-1) / JW)
       
       for j = j1,j2 do
         assert (0 <= j and j < KW)
@@ -3292,7 +3292,7 @@ end
 --
 --      -- pillar in middle of special arch
 --      if link.where == "wide" then
---        long = math.round((long-1) / 2)
+--        long = math.floor((long-1) / 2)
 --        x, y  = x+long*ax,  y+long*ay
 --        ex,ey = ex-long*ax, ey-long*ay
 --
@@ -3347,7 +3347,7 @@ end
 --
 --
 --      B_door(c, link, b_combo, x, y, c.floor_h, dir,
---             1 + math.round(info.w / 64), 1, info, door_kind, tag, key_tex)
+--             1 + math.floor(info.w / 64), 1, info, door_kind, tag, key_tex)
 --    else
 --      error("build_link: bad kind: " .. tostring(link.kind))
 --    end
@@ -3565,10 +3565,10 @@ end
         if spot.long >= 7 or
            (spot.long >= 5 and (WINDOW.c_h - WINDOW.f_h) < 72)
         then
-          local mx1 = math.round((x1+x2)/2)
-          local my1 = math.round((y1+y2)/2)
-          local mx2 = math.round((x1+x2+1)/2)
-          local my2 = math.round((y1+y2+1)/2)
+          local mx1 = math.floor((x1+x2)/2)
+          local my1 = math.floor((y1+y2)/2)
+          local mx2 = math.floor((x1+x2+1)/2)
+          local my2 = math.floor((y1+y2+1)/2)
           fill (c, mx1,my1, mx2,my2, { solid=D.combo.wall })
         end
       else
@@ -3739,7 +3739,7 @@ function build_grotto(c, x1,y1, x2,y2)
   local WALL = { solid=c.combo.wall }
 
   for y = y1+1, y2-1, 2 do
-    for x = x1+1+(math.round(y/2)%2)*2, x2-3, 4 do
+    for x = x1+1+(math.floor(y/2)%2)*2, x2-3, 4 do
       gap_fill(c, x-2,y, x-2,y, WALL)
       gap_fill(c, x+2,y, x+2,y, WALL)
 
@@ -3770,8 +3770,8 @@ function build_pacman_level(c)
   local mid_fab = GAME.FACTORY.PREFABS[rand.pick(PACMAN_MID_FABS)]
   assert(mid_fab)
 
-  local mid_x = 32 - math.round(mid_fab.long/2)
-  local mid_y = 30 - math.round(mid_fab.deep/2)
+  local mid_x = 32 - math.floor(mid_fab.long/2)
+  local mid_y = 30 - math.floor(mid_fab.deep/2)
 
   local top_fab = GAME.FACTORY.PREFABS[rand.pick(PACMAN_CORN_FABS)]
   local bot_fab = GAME.FACTORY.PREFABS[rand.pick(PACMAN_CORN_FABS)]
@@ -4605,7 +4605,7 @@ sel(B.on_path, "YES", "NO"))
 
       local skew = 1.0 + rand.skew() * 0.35
 
-      local kill_blk = math.round(rec.total_blk * c.space_factor / 100 * skew)
+      local kill_blk = math.floor(rec.total_blk * c.space_factor / 100 * skew)
 
       if kill_blk >= rec.total_blk then
         for pos = 1,rec.long do
@@ -4660,7 +4660,7 @@ sel(B.on_path, "YES", "NO"))
 
       local skew = 1.0 + rand.skew() * 0.35
 
-      local kill_blk = math.round(rec.total_blk * c.space_factor / 100 * skew)
+      local kill_blk = math.floor(rec.total_blk * c.space_factor / 100 * skew)
 
       if kill_blk >= rec.total_blk then
         for pos = 1,rec.long do
@@ -4698,7 +4698,7 @@ sel(B.on_path, "YES", "NO"))
 -- gui.printf("GUILLOTINE: SPACE:%d  |  min:%1.1f max:%1.1f @avg:%1.1f --> new_deep:%1.2f\n",
 --   (c.space_factor/10), t_min, t_max, t_avg, new_deep)
 
-      new_deep = math.round(new_deep)
+      new_deep = math.floor(new_deep)
 
       if new_deep <= 0 then
         for pos = 1,rec.long do
@@ -4960,7 +4960,7 @@ gui.debugf("  CELL:   (%d,%d) .. (%d,%d)\n", c.bx1,c.by1, c.bx2,c.by2)
           y = y1 + i*h/(count+1)
         end
 
-        local spot = add_special_pickup_spot(c, math.round(x), math.round(y), 32,32, 200)
+        local spot = add_special_pickup_spot(c, math.floor(x), math.floor(y), 32,32, 200)
 
         spot.vista_side = side
       end
@@ -5411,7 +5411,7 @@ gui.debugf("  EDGE1:%s  EDGE2:%s\n", edge1 or "OK", edge2 or "OK")
       -- limit width to reasonable values (128 or 256 units)
           if long == 3 then long = 2
       elseif long >= 5 and rand.odds(95) then
-        local pos = math.round( (long - 4 + rand.irange(0,1)) / 2)
+        local pos = math.floor( (long - 4 + rand.irange(0,1)) / 2)
         x, y = x + pos*ax, y + pos*ay
         long = 4
       end
@@ -5491,8 +5491,8 @@ gui.debugf("  EDGE1:%s  EDGE2:%s\n", edge1 or "OK", edge2 or "OK")
     local function link_walk_pos(L)
       local dx,dy = dir_to_delta(10-L.side) -- inwards
 
-      local x = math.round((L.link.x1 + L.link.x2) / 2)
-      local y = math.round((L.link.y1 + L.link.y2) / 2)
+      local x = math.floor((L.link.x1 + L.link.x2) / 2)
+      local y = math.floor((L.link.y1 + L.link.y2) / 2)
 
       return x+dx, y+dy
     end
@@ -5613,8 +5613,8 @@ gui.debugf("  EDGE1:%s  EDGE2:%s\n", edge1 or "OK", edge2 or "OK")
         if K.kind == "empty" then K.kind = "room" end
 
         -- TODO: prefer block is not on stair/lift
-        local rx = math.round((K.x1+K.x2)/2)
-        local ry = math.round((K.y1+K.y2)/2)
+        local rx = math.floor((K.x1+K.x2)/2)
+        local ry = math.floor((K.y1+K.y2)/2)
 
         for i = 1,#link_list do
           find_path("room", link_list[i], rx, ry)
@@ -5635,12 +5635,12 @@ gui.debugf("  EDGE1:%s  EDGE2:%s\n", edge1 or "OK", edge2 or "OK")
 
           if K.kx == 1 then qx = K.x2
       elseif K.kx == 3 then qx = K.x1
-      else   qx = math.round((K.x1+K.x2) / 2)
+      else   qx = math.floor((K.x1+K.x2) / 2)
       end
 
           if K.ky == 1 then qy = K.y2
       elseif K.ky == 3 then qy = K.y1
-      else   qy = math.round((K.y1+K.y2) / 2)
+      else   qy = math.floor((K.y1+K.y2) / 2)
       end
 
       find_path("room", rand.pick(link_list), qx, qy)
@@ -6594,7 +6594,7 @@ gui.debugf("add_quest_object: %s @ (%d,%d)\n", name, x, y)
     if not info then error("Unknown boss: " .. name) end
 
     local count = 1
-    if info.hp < 900 then count = math.round(1900/info.hp) end
+    if info.hp < 900 then count = math.floor(1900/info.hp) end
 
     for i = 1,count do
       add_quest_object(c, name)
@@ -6716,8 +6716,8 @@ gui.debugf("add_wall_stuff: %s @ (%d,%d) block:(%d,%d) dir:%d\n",
     if c.quest.return_args then
       local dx,dy = dir_to_delta(dir)
 
-      local x  = math.round((K.x1+K.x2) / 2) + dx * 4
-      local y  = math.round((K.y1+K.y2) / 2) + dy * 4
+      local x  = math.floor((K.x1+K.x2) / 2) + dx * 4
+      local y  = math.floor((K.y1+K.y2) / 2) + dy * 4
 
       sort_fab_locs(c, "near", x, y)
 
@@ -7037,8 +7037,8 @@ gui.debugf("add_prefab: %s  dir:%d\n", def.name, dir)
       if (c.x==1 and c.y==1) or (c.x==PLAN.w and c.y==PLAN.h) then
         -- OK
       elseif math.max(PLAN.w,PLAN.h) >= 5 and
-             c.x == math.round(PLAN.w/2 + 0.6) and
-             c.y == math.round(PLAN.h/2 + 0.6) then
+             c.x == math.floor(PLAN.w/2 + 0.6) and
+             c.y == math.floor(PLAN.h/2 + 0.6) then
         -- OK
       else return end
     else
diff --git a/scripts/094/monster.lua b/scripts/094/monster.lua
index 8d6b740d3..ba450120b 100644
--- a/scripts/094/monster.lua
+++ b/scripts/094/monster.lua
@@ -112,7 +112,7 @@ function rectangle_to_spots(c, x,y, x2,y2)
   local spots = {}
 
   local function carve_it_up(x,y, w,h)
-    local w2, h2 = math.round(w/2), math.round(h/2)
+    local w2, h2 = math.floor(w/2), math.floor(h/2)
     
     if h > 2 then
       carve_it_up(x, y, w, h2)
@@ -525,7 +525,7 @@ function simulate_battle(HM, mon_set, quest)
       assert(info)
 
       remain_shots = 1 + gui.random() + gui.random()
-      remain_shots = math.round(remain_shots * info.rate)
+      remain_shots = math.floor(remain_shots * info.rate)
 
       if remain_shots < 1 then remain_shots = 1 end
 
@@ -939,7 +939,7 @@ function distribute_pickups(c, HM, backtrack)
     local idx = rand.index_by_probs(probs)
     local th_info = infos[idx]
 
-    local count = 1 + math.round(R / th_info.give)
+    local count = 1 + math.floor(R / th_info.give)
     if GAME.FACTORY.caps.blocky_items then count = 1 end
 
     if th_info.clu_max then count = math.min(count, th_info.clu_max) end
@@ -1306,7 +1306,7 @@ function battle_in_cell(c)
     local probs = { 30     }
 
     for name,info in pairs(GAME.FACTORY.monsters) do
-      if (info.pow < T*2) and (fp >= math.round(info.fp)) then
+      if (info.pow < T*2) and (fp >= math.floor(info.fp)) then
 
         local prob = info.prob * (c.mon_prefs[name] or 1)
 
@@ -1337,7 +1337,7 @@ function battle_in_cell(c)
 
   local function decide_monster_horde(info)
     local horde = 1
-    local max_horde = 1 + math.round(T / info.pow)
+    local max_horde = 1 + math.floor(T / info.pow)
 
     if info.hp <= 500 and rand.odds(30) then horde = horde + 1 end
     if info.hp <= 100 then horde = horde + rand.index_by_probs { 90, 40, 10, 3, 0.5 } end
@@ -1391,7 +1391,7 @@ function battle_in_cell(c)
 
     for name,info in pairs(GAME.FACTORY.monsters) do
       if (info.cage_fallback) or 
-         ((info.pow < T*2/x_horde) and (fp >= math.round(info.fp)))
+         ((info.pow < T*2/x_horde) and (fp >= math.floor(info.fp)))
       then
         local prob = info.cage_prob or info.cage_fallback or 0
 
@@ -1455,8 +1455,8 @@ function battle_in_cell(c)
       local horde = decide_cage_horde(spot, info)
 
       for i = 1,horde do
-        local dx = math.round((i-1)%2) * 64
-        local dy = math.round((i-1)/2) * 64
+        local dx = math.floor((i-1)%2) * 64
+        local dy = math.floor((i-1)/2) * 64
 
         local angle = rand.irange(0,7) * 45
         local options = { [SK]=true }
@@ -1492,8 +1492,8 @@ function battle_in_cell(c)
         local horde = decide_cage_horde(spot, info)
 
         for i = 1,horde do
-          local dx = math.round((i-1)%2) * 64
-          local dy = math.round((i-1)/2) * 64
+          local dx = math.floor((i-1)%2) * 64
+          local dy = math.floor((i-1)/2) * 64
 
           local angle = delta_to_angle(5-(spot.x+dx/64), 5-(spot.y+dy/64))
           local options = { [SK]=true }
diff --git a/scripts/094/plan_dm.lua b/scripts/094/plan_dm.lua
index d8459a310..a2674edfe 100644
--- a/scripts/094/plan_dm.lua
+++ b/scripts/094/plan_dm.lua
@@ -402,7 +402,7 @@ function plan_dm_arena(level)
 
     rand.shuffle(locs)
 
-    local num_f = math.round((PLAN.w + PLAN.h) / 4)
+    local num_f = math.floor((PLAN.w + PLAN.h) / 4)
 
     while #locs > 0 and num_f > 0 do
 
@@ -483,7 +483,7 @@ function plan_dm_arena(level)
       end
     end
     
-    ob_size = math.clamp(low, math.round(rand.irange(low, high) * result_skew), high)
+    ob_size = math.clamp(low, math.floor(rand.irange(low, high) * result_skew), high)
     goto foundsize
   end
 
@@ -521,7 +521,7 @@ function plan_dm_arena(level)
     local def_large = PARAM.float_level_upper_bound - def_small or 42
 
     -- this basically ramps up
-    ob_size = math.round(def_small + along * def_large)
+    ob_size = math.floor(def_small + along * def_large)
   end
 
   ::foundsize::
@@ -585,8 +585,8 @@ function plan_dm_arena(level)
   PLAN.cells[pw][ph].require_player = true
 
   -- guarantee at least one weapon (central cell)
-  local mx = math.round((PLAN.w+1)/2)
-  local my = math.round((PLAN.h+1)/2)
+  local mx = math.floor((PLAN.w+1)/2)
+  local my = math.floor((PLAN.h+1)/2)
 
   PLAN.cells[mx][my].require_weapon = true
 
diff --git a/scripts/094/planner.lua b/scripts/094/planner.lua
index 2be350b45..8480eea6d 100644
--- a/scripts/094/planner.lua
+++ b/scripts/094/planner.lua
@@ -354,7 +354,7 @@ function std_decide_quests(Level, QUEST_TAB, LEN_PROBS)
       end
     end
     
-    ob_size = math.clamp(low, math.round(rand.irange(low, high) * result_skew), high)
+    ob_size = math.clamp(low, math.floor(rand.irange(low, high) * result_skew), high)
     goto foundsize
   end
 
@@ -392,7 +392,7 @@ function std_decide_quests(Level, QUEST_TAB, LEN_PROBS)
     local def_large = PARAM.float_level_upper_bound - def_small or 42
 
     -- this basically ramps up
-    ob_size = math.round(def_small + along * def_large)
+    ob_size = math.floor(def_small + along * def_large)
   end
 
   ::foundsize::
@@ -1434,8 +1434,8 @@ c.along, Q.level, Q.sub_level, c.room_type.name)
 
     -- add very first room somewhere in lower-left quarter of map
     if not Q.parent and Q.level == 1 then
-      local x = rand.irange(1, math.round(PLAN.w / 2))
-      local y = rand.irange(1, math.round(PLAN.h / 2))
+      local x = rand.irange(1, math.floor(PLAN.w / 2))
+      local y = rand.irange(1, math.floor(PLAN.h / 2))
 
       local c = create_cell(x, y, Q, 1, Q.combo)
 
@@ -1459,9 +1459,9 @@ c.along, Q.level, Q.sub_level, c.room_type.name)
     local want_len = Q.want_len
     if OB_CONFIG.game ~= "hexen" then
       if want_len >= 4 and Q.ob_size < 25 then
-        want_len = math.round(want_len * 0.85 - gui.random())
+        want_len = math.floor(want_len * 0.85 - gui.random())
       elseif Q.ob_size > 50 then
-        want_len = math.round(want_len * 1.35 + gui.random())
+        want_len = math.floor(want_len * 1.35 + gui.random())
       end
     end
 
@@ -2041,7 +2041,7 @@ gui.debugf("qlist now:\n%s\n\n", table.tostr(qlist,2))
 --T2 = GAME.FACTORY.themes["CAVE"]
 
     -- choose change-over point
-    local mid_q = math.round(#PLAN.quests / 2 + gui.random())
+    local mid_q = math.floor(#PLAN.quests / 2 + gui.random())
 
     if #PLAN.quests >= 4 then
       mid_q = mid_q + (rand.index_by_probs { 1,3,1 }) - 2
diff --git a/scripts/094/writer.lua b/scripts/094/writer.lua
index af81ceab1..4ddc975b3 100644
--- a/scripts/094/writer.lua
+++ b/scripts/094/writer.lua
@@ -408,7 +408,7 @@ function write_level(lev_name)
     local function line_length(L)
       local dx = L.ex - L.sx
       local dy = L.ey - L.sy
-      return math.round(math.sqrt(dx*dx + dy*dy) + 0.5)
+      return math.floor(math.sqrt(dx*dx + dy*dy) + 0.5)
     end
 
     local function frag_pair(f,b,norm, x,y,dx,dy)
@@ -940,11 +940,11 @@ function write_wolf_level()
 
         if kind.dirs and th.angle then
           if kind.dirs == "player" then
-            local offset = math.round((360 - th.angle + 135) / 90) % 4
+            local offset = math.floor((360 - th.angle + 135) / 90) % 4
             assert(0 <= offset and offset <= 3)
             obj = obj + offset
           else
-            local offset = math.round((th.angle + 45) / 90) % 4
+            local offset = math.floor((th.angle + 45) / 90) % 4
             assert(0 <= offset and offset <= 3)
             obj = obj + offset
           end
diff --git a/scripts/area.lua b/scripts/area.lua
index 0e0d2ce5f..686cc6e3e 100644
--- a/scripts/area.lua
+++ b/scripts/area.lua
@@ -1674,7 +1674,7 @@ function Area_locate_chunks(LEVEL, SEEDS)
 
 
   local function find_sized_chunks(A, seed_list, pass, LEVEL)
-    local dx = math.round(pass / 10) - 1
+    local dx = math.floor(pass / 10) - 1
     local dy = (pass % 10) - 1
 
     local use_prob = USE_PROBS[pass] or 99
@@ -2908,7 +2908,7 @@ function Area_create_rooms(LEVEL, SEEDS)
 
   if SHAPE_GRAMMAR.force_level_size then
     LEVEL.map_W = SHAPE_GRAMMAR.force_level_size
-    LEVEL.map_H = 1 + math.round(LEVEL.map_W * 0.8)
+    LEVEL.map_H = 1 + math.floor(LEVEL.map_W * 0.8)
     SEEDS = Seed_init(LEVEL)
   end
 
diff --git a/scripts/brush.lua b/scripts/brush.lua
index 682cbe0ab..96530e060 100644
--- a/scripts/brush.lua
+++ b/scripts/brush.lua
@@ -1100,7 +1100,7 @@ function brushlib.reverse(brush)
 
   -- second, actually reverse the coord tables
 
-  for i = 1, math.round(#xy_coords / 2) do
+  for i = 1, math.floor(#xy_coords / 2) do
     local k = #xy_coords + 1 - i
 
     local C1 = brush[xy_coords[i].idx]
diff --git a/scripts/cave.lua b/scripts/cave.lua
index a307b7ffd..e87cfdbd0 100644
--- a/scripts/cave.lua
+++ b/scripts/cave.lua
@@ -371,8 +371,8 @@ end
 
 
 function Cave_cell_touches_map_edge(LEVEL, area, cx, cy)
-  local sx = area.base_sx + math.round((cx - 1) / 2)
-  local sy = area.base_sy + math.round((cy - 1) / 2)
+  local sx = area.base_sx + math.floor((cx - 1) / 2)
+  local sy = area.base_sy + math.floor((cy - 1) / 2)
 
   if (cx % 2) == 0 then
     if sx >= LEVEL.absolute_x2 then return true end
@@ -398,8 +398,8 @@ function Cave_cell_touches_room(area, cx, cy, R, SEEDS)
     local nx, ny = geom.nudge(cx, cy, dir)
 
     -- get seed coordinate of neighbor cell
-    local sx = area.base_sx + math.round((nx - 1) / 2)
-    local sy = area.base_sy + math.round((ny - 1) / 2)
+    local sx = area.base_sx + math.floor((nx - 1) / 2)
+    local sy = area.base_sy + math.floor((ny - 1) / 2)
 
     if not Seed_valid(sx, sy) then goto continue end
 
@@ -1483,7 +1483,7 @@ function Cave_bunch_areas(R, mode, LEVEL)
 
   setup()
 
-  local try_count = math.round(#area.walk_floors / rand.sel(50, 8, 14))
+  local try_count = math.floor(#area.walk_floors / rand.sel(50, 8, 14))
 
   for i = 1, try_count do
     local B1 = pick_start_area()
@@ -2625,7 +2625,7 @@ function Cave_decorations(R)
     local quota = #locs * perc / 100
 
     quota = quota * rand.range(0.8, 1.2)
-    quota = math.round(quota + gui.random())
+    quota = math.floor(quota + gui.random())
 
     -- very rarely add lots of torches
     if area.torch_mode ~= "few" and rand.odds(1) then
@@ -3995,7 +3995,7 @@ function Cave_build_a_park(LEVEL, R, entry_h, SEEDS)
 
     -- extra health for damaging liquid
     if LEVEL.liquid.damage then
-      R.hazard_health = R.hazard_health + math.round(B.size / 4)
+      R.hazard_health = R.hazard_health + math.floor(B.size / 4)
     end
   end
 
diff --git a/scripts/grower.lua b/scripts/grower.lua
index 43242a597..2125de4c7 100644
--- a/scripts/grower.lua
+++ b/scripts/grower.lua
@@ -1083,11 +1083,11 @@ function Grower_decide_extents(LEVEL)
     end
   end
 
-  assert(math.round(LEVEL.map_W) < SEED_W)
-  assert(math.round(LEVEL.map_H) < SEED_H)
+  assert(math.floor(LEVEL.map_W) < SEED_W)
+  assert(math.floor(LEVEL.map_H) < SEED_H)
 
-  local map_x1 = 1 + math.round((SEED_W - LEVEL.map_W) / 2)
-  local map_y1 = 1 + math.round((SEED_H - LEVEL.map_H) / 2)
+  local map_x1 = 1 + math.floor((SEED_W - LEVEL.map_W) / 2)
+  local map_y1 = 1 + math.floor((SEED_H - LEVEL.map_H) / 2)
 
   local map_x2 = map_x1 + LEVEL.map_W - 1
   local map_y2 = map_y1 + LEVEL.map_H - 1
@@ -1142,17 +1142,17 @@ function Grower_decide_extents(LEVEL)
 
   local base = (LEVEL.map_W - 12) * 0.72
 
-  LEVEL.min_rooms = math.max(3, math.round(base / 3))
-  LEVEL.max_rooms = math.max(6, math.round(base))
+  LEVEL.min_rooms = math.max(3, math.floor(base / 3))
+  LEVEL.max_rooms = math.max(6, math.floor(base))
 
   -- add extra rooms based on extra size and area multiplier
 
   if LEVEL.size_multiplier then
     if LEVEL.size_multiplier < 1 then
-      LEVEL.max_rooms = math.round(LEVEL.max_rooms * ((1 - LEVEL.size_multiplier)+1) * 2/3)
+      LEVEL.max_rooms = math.floor(LEVEL.max_rooms * ((1 - LEVEL.size_multiplier)+1) * 2/3)
     end
     if LEVEL.area_multiplier < 1 then
-      LEVEL.max_rooms = math.round(LEVEL.max_rooms * ((1 - LEVEL.area_multiplier)+1) * 2/3)
+      LEVEL.max_rooms = math.floor(LEVEL.max_rooms * ((1 - LEVEL.area_multiplier)+1) * 2/3)
     end
   end
 
@@ -1173,7 +1173,7 @@ function Grower_decide_extents(LEVEL)
 
   -- calculate the coverage target
 
-  LEVEL.min_coverage = math.round(LEVEL.map_W * LEVEL.map_H * 0.65)
+  LEVEL.min_coverage = math.floor(LEVEL.map_W * LEVEL.map_H * 0.65)
 
   if LEVEL.has_streets then
     gui.printf("--==| Streets Mode activated! |==--\n\n")
@@ -1188,7 +1188,7 @@ function Grower_decide_extents(LEVEL)
     if PARAM.linear_start ~= "default" then
       if PARAM.linear_start == "all" then
         LEVEL.has_linear_start = true
-      elseif rand.odds(math.round(PARAM.linear_start)) then
+      elseif rand.odds(math.floor(PARAM.linear_start)) then
         LEVEL.has_linear_start = true
       end
     end
@@ -2079,11 +2079,11 @@ stderrf("prelim_conn %s --> %s : S=%s dir=%d\n", c_out.R1.name, c_out.R2.name, S
 
   local function get_iteration_range(T)
     if is_create then
-      local dx = math.min(10, math.round(SEED_W / 4))
-      local dy = math.min(10, math.round(SEED_H / 4))
+      local dx = math.min(10, math.floor(SEED_W / 4))
+      local dy = math.min(10, math.floor(SEED_H / 4))
 
-      local mx = math.round(SEED_W / 2)
-      local my = math.round(SEED_H / 2)
+      local mx = math.floor(SEED_W / 2)
+      local my = math.floor(SEED_H / 2)
 
       -- the exit room is alway placed near top of map
       if cur_rule.absolute_pos == "top" or cur_rule.absolute_pos == "corner" then
@@ -3161,9 +3161,9 @@ end
 
     -- check that it straddles at right spot
     if T.transpose then
-      if by1 ~= R.symmetry.y - math.round((W-1) / 2) then return false end
+      if by1 ~= R.symmetry.y - math.floor((W-1) / 2) then return false end
     else
-      if bx1 ~= R.symmetry.x - math.round((W-1) / 2) then return false end
+      if bx1 ~= R.symmetry.x - math.floor((W-1) / 2) then return false end
     end
 
     if match_or_install_pat_raw(what, T) then
@@ -4051,7 +4051,7 @@ function Grower_sprout_room(SEEDS, LEVEL, R)
     Grower_grammatical_room(SEEDS, LEVEL, R, "sprout")
   end
 
-  if R.is_street and R:prelim_conn_num(LEVEL) < math.clamp(1, math.round(R.svolume/64), 10) then
+  if R.is_street and R:prelim_conn_num(LEVEL) < math.clamp(1, math.floor(R.svolume/64), 10) then
     Grower_grammatical_room(SEEDS, LEVEL, R, "sprout")
   end
 
diff --git a/scripts/item.lua b/scripts/item.lua
index e2aefdc5d..e12c0c4d8 100644
--- a/scripts/item.lua
+++ b/scripts/item.lua
@@ -141,7 +141,7 @@ function Player_give_stuff(hmodel, give_list)
 
     elseif give.ammo then
       gui.debugf("Giving [%s] ammo: %dx %s\n",
-                 hmodel.class, math.round(give.count), give.ammo)
+                 hmodel.class, math.floor(give.count), give.ammo)
 
       hmodel.stats[give.ammo] = (hmodel.stats[give.ammo] or 0) + give.count
 
@@ -301,14 +301,14 @@ function Player_weapon_palettes(LEVEL)
 
     -- Note: result is often longer than strictly required
 
-    local num_low  = math.round(total / 2 + gui.random())
+    local num_low  = math.floor(total / 2 + gui.random())
     local num_high = total - num_low
 
     insert_multiple(list, num_low,  Low)
     insert_multiple(list, num_high, High)
 
     if total >= 2 then
-      local num_very = math.round(total / 6 + gui.random())
+      local num_very = math.floor(total / 6 + gui.random())
 
       insert_multiple(list, num_very, Lowest)
       insert_multiple(list, num_very, Highest)
@@ -341,7 +341,7 @@ function Player_weapon_palettes(LEVEL)
     local pal = {}
 
     -- decide number of "normal" weapons : at least one!
-    local normal_num = math.round(total / 3 + gui.random())
+    local normal_num = math.floor(total / 3 + gui.random())
     if normal_num < 1 then normal_num = 1 end
 
     got_weaps = table.copy(got_weaps)
@@ -872,7 +872,7 @@ function Item_pickups_for_class(LEVEL, CL)
       elseif max_num * each_qty <= qty then
         count = max_num - rand.sel(20,1,0)
       else
-        count = 1 + math.round(qty / each_qty)
+        count = 1 + math.floor(qty / each_qty)
       end
     end
 
diff --git a/scripts/layout.lua b/scripts/layout.lua
index 3e86b777e..ffb07c851 100644
--- a/scripts/layout.lua
+++ b/scripts/layout.lua
@@ -1054,7 +1054,7 @@ gui.debugf("MonRelease in %s : kind --> %s\n",
 
     local qty = rand.index_by_probs({ 40,40,20,5 })
 
-    if STYLE.traps == "few"   then math.round((qty + 1) / 2) end
+    if STYLE.traps == "few"   then math.floor((qty + 1) / 2) end
     if STYLE.traps == "more"  then qty = qty + 1 end
     if STYLE.traps == "heaps" then qty = qty + 2 end
 
@@ -2802,18 +2802,18 @@ function Layout_indoor_lighting(LEVEL)
 
   local LIGHT_LEVELS =
   {
-    bright   = math.round(224 * PARAM.float_overall_lighting_mult),
-    normal   = math.round(192 * PARAM.float_overall_lighting_mult),
-    dark     = math.round(160 * PARAM.float_overall_lighting_mult),
-    verydark = math.round(128 * PARAM.float_overall_lighting_mult),
+    bright   = math.floor(224 * PARAM.float_overall_lighting_mult),
+    normal   = math.floor(192 * PARAM.float_overall_lighting_mult),
+    dark     = math.floor(160 * PARAM.float_overall_lighting_mult),
+    verydark = math.floor(128 * PARAM.float_overall_lighting_mult),
   }
 
   local CAVE_LEVELS =
   {
-    bright   = math.round(192 * PARAM.float_overall_lighting_mult),
-    normal   = math.round(160 * PARAM.float_overall_lighting_mult),
-    dark     = math.round(128 * PARAM.float_overall_lighting_mult),
-    verydark = math.round(96 * PARAM.float_overall_lighting_mult),
+    bright   = math.floor(192 * PARAM.float_overall_lighting_mult),
+    normal   = math.floor(160 * PARAM.float_overall_lighting_mult),
+    dark     = math.floor(128 * PARAM.float_overall_lighting_mult),
+    verydark = math.floor(96 * PARAM.float_overall_lighting_mult),
   }
 
   local function sky_light_to_keyword()
@@ -2848,7 +2848,7 @@ function Layout_indoor_lighting(LEVEL)
       local JITTER = {0, 0, 0, -16, 16}
       base_light = base_light + rand.pick(JITTER)
     else
-      local JITTER = {0, 0, 0, -math.round(base_light * 0.1), math.round(base_light * 0.1)}
+      local JITTER = {0, 0, 0, -math.floor(base_light * 0.1), math.floor(base_light * 0.1)}
       base_light = base_light + rand.pick(JITTER)
     end
 
diff --git a/scripts/level.lua b/scripts/level.lua
index a05b43983..90776079f 100644
--- a/scripts/level.lua
+++ b/scripts/level.lua
@@ -196,7 +196,7 @@ function Level_determine_map_size(LEV)
       end
     end
 
-    ob_size = math.clamp(low, math.round(rand.irange(low, high) * result_skew), high)
+    ob_size = math.clamp(low, math.floor(rand.irange(low, high) * result_skew), high)
   end
 
   if ob_size == gui.gettext("Episodic") or 
@@ -223,7 +223,7 @@ function Level_determine_map_size(LEV)
     local def_large = PARAM.float_level_upper_bound - def_small or 42
 
     -- this basically ramps up
-    W = math.round(def_small + along * def_large)
+    W = math.floor(def_small + along * def_large)
   else
 
     -- Single Size --
@@ -244,7 +244,7 @@ function Level_determine_map_size(LEV)
 
   gui.printf("Initial size for " .. LEV.name .. ": " .. W .. "\n")
 
-  local H = 1 + math.round(W * 0.8)
+  local H = 1 + math.floor(W * 0.8)
 
   return W, H
 end
@@ -1200,7 +1200,7 @@ function Episode_plan_weapons()
     end
 
     quota = quota * (PARAM.weapon_factor or 1)
-    quota = math.round(quota)
+    quota = math.floor(quota)
 
     if quota < 1 then quota = 1 end
 
@@ -1352,7 +1352,7 @@ function Episode_plan_weapons()
 
       if rand.odds(30) then lev_idx = lev_idx + 1 end
 
-      lev_idx = math.round(lev_idx * rand.pick({ 1.0, 1.3, 1.6 }))
+      lev_idx = math.floor(lev_idx * rand.pick({ 1.0, 1.3, 1.6 }))
     end
 
     -- ensure it is valid
@@ -1515,7 +1515,7 @@ function Episode_plan_weapons()
   local function reduce_weapon_gaps(level_list)
     local max_gap = 2
 
-    max_gap = max_gap + math.round(#level_list / 20)
+    max_gap = max_gap + math.floor(#level_list / 20)
 
     if OB_CONFIG.weapons == "very_late" then max_gap = max_gap + 2 end
     if OB_CONFIG.weapons == "later"     then max_gap = max_gap + 1 end
@@ -2328,14 +2328,14 @@ function Level_choose_darkness(LEVEL)
     --prob = style_sel("darkness", 0, 10, 30, 90) --Original
   end
 
-  LEVEL.sky_light  = math.round(rand.pick(SKY_LIGHT_NORMAL) * PARAM.float_overall_lighting_mult)
+  LEVEL.sky_light  = math.floor(rand.pick(SKY_LIGHT_NORMAL) * PARAM.float_overall_lighting_mult)
   LEVEL.sky_shadow = 32
 
   if rand.odds(prob) then
     gui.printf("Level is dark.\n")
 
     LEVEL.is_dark = true
-    LEVEL.sky_light = math.round(rand.pick(SKY_LIGHT_DARK) * PARAM.float_overall_lighting_mult)
+    LEVEL.sky_light = math.floor(rand.pick(SKY_LIGHT_DARK) * PARAM.float_overall_lighting_mult)
     LEVEL.sky_shadow = 32
   end
 
diff --git a/scripts/monster.lua b/scripts/monster.lua
index 6abcead86..b1805cf23 100644
--- a/scripts/monster.lua
+++ b/scripts/monster.lua
@@ -450,13 +450,13 @@ function Monster_zone_palettes(LEVEL)
       skip_perc = skip_perc / 2
     end
 
-    quants[0] = math.round(total * skip_perc / 100 + gui.random() * 0.7)
+    quants[0] = math.floor(total * skip_perc / 100 + gui.random() * 0.7)
     total = total - quants[0]
 
-    quants[2] = math.round(total * rand.range(0.3, 0.7) + gui.random())
+    quants[2] = math.floor(total * rand.range(0.3, 0.7) + gui.random())
     total = total - quants[2]
 
-    quants[1] = math.round(total * rand.range(0.3, 0.7) + gui.random())
+    quants[1] = math.floor(total * rand.range(0.3, 0.7) + gui.random())
     total = total - quants[1]
 
     quants[3] = total
@@ -523,7 +523,7 @@ function Monster_zone_palettes(LEVEL)
       gui.debugf("   %-12s* %1.2f\n", mon, qty)
     end
     
-    gui.debugf("   TOUGHNESS: %d\n", math.round(palette_toughness(pal)))
+    gui.debugf("   TOUGHNESS: %d\n", math.floor(palette_toughness(pal)))
   end
 
 
@@ -585,8 +585,8 @@ function Monster_split_spots(list, max_size)
   for _,spot in pairs(list) do
     local w, h = geom.box_size(spot.x1, spot.y1, spot.x2, spot.y2)
 
-    local XN = math.round(w / max_size)
-    local YN = math.round(h / max_size)
+    local XN = math.floor(w / max_size)
+    local YN = math.floor(h / max_size)
 
     if XN < 2 and YN < 2 then
       table.insert(new_list, spot)
@@ -603,8 +603,8 @@ function Monster_split_spots(list, max_size)
 
       local new_spot = table.copy(spot)
 
-      new_spot.x1 = math.round(x1) ; new_spot.y1 = math.round(y1)
-      new_spot.x2 = math.round(x2) ; new_spot.y2 = math.round(y2)
+      new_spot.x1 = math.floor(x1) ; new_spot.y1 = math.floor(y1)
+      new_spot.x2 = math.floor(x2) ; new_spot.y2 = math.floor(y2)
       new_spot.marked = nil
 
       table.insert(new_list, new_spot)
@@ -874,11 +874,11 @@ function Monster_fill_room(LEVEL, R, SEEDS)
     gui.debugf("raw number_of_kinds in %s : tally:%d / %d seeds | base:%1.2f factor:%1.2f ---> %1.2f\n",
                R.name, fodder_tally, R.svolume, base_num, factor, num)
 --]]
-    num = math.round(base_num)
+    num = math.floor(base_num)
 
     num = math.clamp(1, num, 5)
 
-    gui.debugf("number_of_kinds: %d (base: %d)\n", num, math.round(base_num))
+    gui.debugf("number_of_kinds: %d (base: %d)\n", num, math.floor(base_num))
 
     return num
   end
@@ -1127,8 +1127,8 @@ function Monster_fill_room(LEVEL, R, SEEDS)
      for _,spot in pairs(spot_list) do
       local w, h = geom.box_size(spot.x1, spot.y1, spot.x2, spot.y2)
 
-      w = math.round(w / 64) ; if w < 1 then w = 1 end
-      h = math.round(h / 64) ; if h < 1 then h = 1 end
+      w = math.floor(w / 64) ; if w < 1 then w = 1 end
+      h = math.floor(h / 64) ; if h < 1 then h = 1 end
 
       count = count + w * h
     end
@@ -1367,7 +1367,7 @@ function Monster_fill_room(LEVEL, R, SEEDS)
       num_kinds = rand.index_by_probs({ 20, 40, 60 })
     else
       local size = math.sqrt(R.svolume)
-      num_kinds = math.round(size / 1.2)
+      num_kinds = math.floor(size / 1.2)
     end
 
     local list = {}
@@ -1708,8 +1708,8 @@ function Monster_fill_room(LEVEL, R, SEEDS)
 
     local w, h = geom.box_size(spot.x1, spot.y1, spot.x2, spot.y2)
 
-    w = math.round(w / rr / 2)
-    h = math.round(h / rr / 2)
+    w = math.floor(w / rr / 2)
+    h = math.floor(h / rr / 2)
 
     return w * h
   end
@@ -2078,7 +2078,7 @@ gui.debugf("wants =\n%s\n\n", table.tostr(wants))
     local tally = fodder_tally
     tally = 3 * (1 + tally ^ 0.7)
 
-    want_total = math.round(tally * qty / 100 + gui.random())
+    want_total = math.floor(tally * qty / 100 + gui.random())
 
 
     -- determine how many of each kind of monster we want
@@ -2208,7 +2208,7 @@ gui.debugf("wants =\n%s\n\n", table.tostr(wants))
       elseif choice == "crazy" then
         min_val = spot_total
       else
-        min_val = math.round(min_val + (spot_total * tab[choice]))
+        min_val = math.floor(min_val + (spot_total * tab[choice]))
       end
 
       return min_val
@@ -2219,8 +2219,8 @@ gui.debugf("wants =\n%s\n\n", table.tostr(wants))
     -- determine maximum number that will fit
     local w, h = geom.box_size(spot.x1,spot.y1, spot.x2,spot.y2)
 
-    w = math.round(w / info.r / 2)
-    h = math.round(h / info.r / 2)
+    w = math.floor(w / info.r / 2)
+    h = math.floor(h / info.r / 2)
 
     assert(w >= 1 and h >= 1)
 
@@ -2566,7 +2566,7 @@ function Monster_show_stats(LEVEL)
 
   local function get_stat(mon)
     local num = LEVEL.mon_stats[mon] or 0
-    local div = math.round(num * 99.8 / total)
+    local div = math.floor(num * 99.8 / total)
     if div == 0 and num > 0 then div = 1 end
     return string.format("%02d", div)
   end
diff --git a/scripts/prefab.lua b/scripts/prefab.lua
index d6352b21b..b1991e413 100644
--- a/scripts/prefab.lua
+++ b/scripts/prefab.lua
@@ -1611,7 +1611,7 @@ function Fab_load_wad(def)
 
     angle = math.clamp(0, angle, 300)
 
-    return 112 + math.round(angle * 16 / 45)
+    return 112 + math.floor(angle * 16 / 45)
   end
 
 
@@ -2249,7 +2249,7 @@ function Fab_replacements(LEVEL, fab)
     -- adjust X offset for split edges
 
     if C.u1 and C.u1 ~= "" and C.u1_along then
-      C.u1 = C.u1 + math.round(C.u1_along)
+      C.u1 = C.u1 + math.floor(C.u1_along)
       C.u1_along = nil
     end
   end
@@ -2637,11 +2637,11 @@ function Fab_find_matches(LEVEL, reqs, match_state)
     end
 
     -- prefab definition defaults to 1
-    local sw = math.round(def.seed_w or 1)
-    local sh = math.round(def.seed_h or 1)
+    local sw = math.floor(def.seed_w or 1)
+    local sh = math.floor(def.seed_h or 1)
 
-    local req_w = math.round(reqs.seed_w or 1)
-    local req_h = math.round(reqs.seed_h or 1)
+    local req_w = math.floor(reqs.seed_w or 1)
+    local req_h = math.floor(reqs.seed_h or 1)
 
     -- "diagonal" prefabs need an exact same square
     if def.where == "diagonal" then
diff --git a/scripts/quest.lua b/scripts/quest.lua
index 5cebe3680..adca0aa4d 100644
--- a/scripts/quest.lua
+++ b/scripts/quest.lua
@@ -912,7 +912,7 @@ function Quest_add_major_quests(LEVEL)
     local each_prob = style_sel("keys", 0, 40, 80, 100)
 
     -- decide maximum number
-    local max_num = 1 + math.round(#LEVEL.rooms / 5)
+    local max_num = 1 + math.floor(#LEVEL.rooms / 5)
 
     for name,_ in pairs(key_tab) do
       if rand.odds(each_prob) then
@@ -938,7 +938,7 @@ function Quest_add_major_quests(LEVEL)
     if not rand.odds(any_prob) then return {} end
 
     -- decide maximum number
-    local max_num = 1 + math.round(#LEVEL.rooms / 5)
+    local max_num = 1 + math.floor(#LEVEL.rooms / 5)
 
     for i = 1, max_num do
       if rand.odds(each_prob) then
@@ -1508,7 +1508,7 @@ function Quest_start_room(LEVEL)
     -- prefer no teleporter
     if not R:has_teleporter() then score = score + 1 end
 
-    gui.debugf("eval_start_room in %s --> space:%d dist:%d %1.2f\n", R.name, space, math.round(R.dist_to_exit or -1), score)
+    gui.debugf("eval_start_room in %s --> space:%d dist:%d %1.2f\n", R.name, space, math.floor(R.dist_to_exit or -1), score)
 
     -- tie breaker
     return score + gui.random() * 2
@@ -1703,7 +1703,7 @@ function Quest_order_by_visit(LEVEL)
     gui.printf("Quest list:\n")
 
     for _,Q in pairs(LEVEL.quests) do
-      gui.printf("  %s : svolume:%d\n", Q.name, math.round(Q.svolume))
+      gui.printf("  %s : svolume:%d\n", Q.name, math.floor(Q.svolume))
     end
   end
 
@@ -3028,7 +3028,7 @@ function Quest_room_themes(LEVEL)
     
     local building_tab = collect_usable_themes("building")
 
-    local max_room_theme = math.round(PARAM.float_max_room_themes or 1)
+    local max_room_theme = math.floor(PARAM.float_max_room_themes or 1)
 
     if not PARAM.bool_avoid_room_theme_reuse or (PARAM.bool_avoid_room_theme_reuse and PARAM.bool_avoid_room_theme_reuse == 1) then
       for theme,odds in pairs(building_tab) do
@@ -3054,7 +3054,7 @@ function Quest_room_themes(LEVEL)
 
     visit_room(LEVEL.start_room, nil, nil, building_tab)
 
-    local max_wall_groups = math.round(PARAM.float_max_indoor_wall_groups or 2)
+    local max_wall_groups = math.floor(PARAM.float_max_indoor_wall_groups or 2)
 
     local the_wall_group_tab = table.copy(LEVEL.theme.wall_groups)
 
diff --git a/scripts/render.lua b/scripts/render.lua
index 19fed8d85..a2a818d01 100644
--- a/scripts/render.lua
+++ b/scripts/render.lua
@@ -40,9 +40,9 @@ function Render_add_exit_sign(E, z, SEEDS, LEVEL)
 
   local len = geom.dist(x1,y1, x2,y2)
 
-  local ofs = math.round(len / 6)
+  local ofs = math.floor(len / 6)
   if len > 340 then
-    ofs = math.round(len / 4)
+    ofs = math.floor(len / 4)
   end
 
   local ax = x1 + ofs * (x2 - x1) / len
@@ -3190,8 +3190,8 @@ function Render_all_street_traffic(LEVEL, SEEDS)
   for _,SPOT in pairs(LEVEL.road_street_traffic_spots) do
 
     -- stagger positions a bit
-    SPOT.x = SPOT.x + math.round(rand.range(-32,32))
-    SPOT.y = SPOT.y + math.round(rand.range(-32,32))
+    SPOT.x = SPOT.x + math.floor(rand.range(-32,32))
+    SPOT.y = SPOT.y + math.floor(rand.range(-32,32))
 
     local T = Trans.spot_transform(SPOT.x, SPOT.y, SPOT.z, SPOT.dir)
     local reqs = {}
@@ -3676,7 +3676,7 @@ function Render_scenic_fabs(LEVEL, SEEDS)
       end
     end
 
-    for i = 1, math.round(area.svolume/32) do
+    for i = 1, math.floor(area.svolume/32) do
       try_decor_here(area)
     end
   end
@@ -4328,7 +4328,7 @@ function Render_cells(LEVEL, area)
     assert(B)
     assert(B.floor_h)
 
-    return string.format("1-%5d-%5d", math.round(B.floor_h + 50000), math.round(50000 - (B.ceil_h or 0)))
+    return string.format("1-%5d-%5d", math.floor(B.floor_h + 50000), math.floor(50000 - (B.ceil_h or 0)))
   end
 
 
diff --git a/scripts/room.lua b/scripts/room.lua
index cf3359d3b..6c98c6ffe 100644
--- a/scripts/room.lua
+++ b/scripts/room.lua
@@ -2285,7 +2285,7 @@ function Room_choose_size(LEVEL, R, not_big)
   if not R.is_start
   or not R.is_secret then
     if LEVEL.area_multiplier then
-      R.floor_limit = math.round(R.floor_limit * LEVEL.area_multiplier)
+      R.floor_limit = math.floor(R.floor_limit * LEVEL.area_multiplier)
     end
     if LEVEL.has_absurd_new_area_rules then
       R.floor_limit = R.floor_limit * 4
@@ -2316,8 +2316,8 @@ function Room_choose_size(LEVEL, R, not_big)
   elseif not LEVEL.is_procedural_gotcha then
 
     if R.is_start then
-      R.size_limit = math.round(R.size_limit / 2)
-      R.floor_limit = math.round(R.floor_limit / 2)
+      R.size_limit = math.floor(R.size_limit / 2)
+      R.floor_limit = math.floor(R.floor_limit / 2)
       R.size_limit = math.clamp(rand.pick({4,8,12,16}),R.size_limit,EXTREME_H)
     end
 
@@ -2333,8 +2333,8 @@ function Room_choose_size(LEVEL, R, not_big)
   -- tame teleporter trunks and hallway exits
   if (not R.grow_parent and not R.is_start)
   or (R.grow_parent and R.grow_parent.is_hallway) then
-    R.size_limit = math.round(R.size_limit / 5)
-    R.floor_limit = math.round(R.floor_limit / 2)
+    R.size_limit = math.floor(R.size_limit / 5)
+    R.floor_limit = math.floor(R.floor_limit / 2)
     R.is_big = false
   end
 end
diff --git a/scripts/seed.lua b/scripts/seed.lua
index 07f1d6e8a..faca5bd6c 100644
--- a/scripts/seed.lua
+++ b/scripts/seed.lua
@@ -364,8 +364,8 @@ function SEED_CLASS.calc_mid_point(S)
     my = (S.y2 + my) / 2
   end
 
-  S.mid_x = math.round(mx)
-  S.mid_y = math.round(my)
+  S.mid_x = math.floor(mx)
+  S.mid_y = math.floor(my)
 end
 
 
@@ -561,8 +561,8 @@ function Seed_init(LEVEL)
   BASE_X = 32
   BASE_Y = 32
 
-  BASE_X = 32 - math.round(SEED_W / 2) * SEED_SIZE
-  BASE_Y = 32 - math.round(SEED_H / 2) * SEED_SIZE
+  BASE_X = 32 - math.floor(SEED_W / 2) * SEED_SIZE
+  BASE_Y = 32 - math.floor(SEED_H / 2) * SEED_SIZE
 
   for sx = 1, SEED_W do
   for sy = 1, SEED_H do
@@ -581,7 +581,7 @@ function Seed_init(LEVEL)
   local depot_y = BASE_Y + SEED_H * SEED_SIZE
 
   for row = 0, 2 do
-  for col = 0, math.round(SEED_W / 3) - 1 do
+  for col = 0, math.floor(SEED_W / 3) - 1 do
     local x = depot_x + col * 3 * SEED_SIZE
     local y = depot_y + row * 6 * SEED_SIZE + 64
 
@@ -985,7 +985,7 @@ function Seed_draw_minimap(SEEDS, LEVEL)
     y1 = (y1 - min_y + ofs_y) * map_H / size
     y2 = (y2 - min_y + ofs_y) * map_H / size
 
-    gui.minimap_draw_line(math.round(x1),math.round(y1), math.round(x2),math.round(y2), color)
+    gui.minimap_draw_line(math.floor(x1),math.floor(y1), math.floor(x2),math.floor(y2), color)
   end
 
 
diff --git a/scripts/title_gen.lua b/scripts/title_gen.lua
index ab8e2149c..3cd44cb7d 100644
--- a/scripts/title_gen.lua
+++ b/scripts/title_gen.lua
@@ -870,7 +870,7 @@ function Title_make_stroke(T, x1,y1, x2,y2)
   x1, y1 = T.func(T, x1, y1)
   x2, y2 = T.func(T, x2, y2)
 
-  gui.title_draw_line(math.round(x1 + T.ofs_x), math.round(y1 + T.ofs_y), math.round(x2 + T.ofs_x), math.round(y2 + T.ofs_y))
+  gui.title_draw_line(math.floor(x1 + T.ofs_x), math.floor(y1 + T.ofs_y), math.floor(x2 + T.ofs_x), math.floor(y2 + T.ofs_y))
 end
 
 
@@ -1032,8 +1032,8 @@ function Title_centered_string(T, mx, my, text, style)
         T.ofs_y = base_ofs - i
       end
 
-      gui.title_prop("box_w", math.round(thick))
-      gui.title_prop("box_h", math.round(thick))
+      gui.title_prop("box_w", math.floor(thick))
+      gui.title_prop("box_h", math.floor(thick))
 
       Title_draw_string(T, text)
     end
@@ -1055,12 +1055,12 @@ function Title_centered_string(T, mx, my, text, style)
   end
 
   if style.font_mode == "gradient" or style.font_mode == "gradient3" then
-    gui.title_prop("grad_y1", math.round(T.y - T.fh + 1))
-    gui.title_prop("grad_y2", math.round(T.y - 1))
+    gui.title_prop("grad_y1", math.floor(T.y - T.fh + 1))
+    gui.title_prop("grad_y2", math.floor(T.y - 1))
   end
 
-  gui.title_prop("box_w", math.round(T.thick))
-  gui.title_prop("box_h", math.round(T.thick))
+  gui.title_prop("box_w", math.floor(T.thick))
+  gui.title_prop("box_h", math.floor(T.thick))
 
   T.ofs_x = base_ofs
   T.ofs_y = base_ofs
@@ -1110,9 +1110,9 @@ function Title_interp_color(list, ity, out)
       local A = list[pos]
       local B = list[pos+1]
 
-      out[1] = math.round(A[1] * (1 - ity) + B[1] * ity)
-      out[2] = math.round(A[2] * (1 - ity) + B[2] * ity)
-      out[3] = math.round(A[3] * (1 - ity) + B[3] * ity)
+      out[1] = math.floor(A[1] * (1 - ity) + B[1] * ity)
+      out[2] = math.floor(A[2] * (1 - ity) + B[2] * ity)
+      out[3] = math.floor(A[3] * (1 - ity) + B[3] * ity)
       return
     end
 
@@ -1203,7 +1203,7 @@ function Title_gen_space_scene()
 
 
   local function draw_big_star(mx, my, r)
-    local r2 = math.round(r * 1.2)
+    local r2 = math.floor(r * 1.2)
 
     local DD = 0.09
 
@@ -1221,7 +1221,7 @@ function Title_gen_space_scene()
 
       if ity < 50 then goto continue end
       
-      ity = math.round(ity)
+      ity = math.floor(ity)
 
       gui.title_prop("color", { ity, ity, ity })
       gui.title_draw_rect(x, y, 1, 1)
@@ -1287,9 +1287,9 @@ function Title_gen_space_scene()
     else
       gui.title_draw_rect(mx, my, 1, 1)
 
-      col[1] = math.round(col[1] * 0.6)
-      col[2] = math.round(col[2] * 0.6)
-      col[3] = math.round(col[3] * 0.6)
+      col[1] = math.floor(col[1] * 0.6)
+      col[2] = math.floor(col[2] * 0.6)
+      col[3] = math.floor(col[3] * 0.6)
 
       gui.title_prop("color", col)
 
@@ -1390,7 +1390,7 @@ function Title_gen_ray_burst()
       Title_interp_color(color_list, ity, col)
 
       gui.title_prop("color", col)
-      gui.title_draw_line(mx, my, math.round(x1), math.round(y1), col)
+      gui.title_draw_line(mx, my, math.floor(x1), math.floor(y1), col)
     end
     end
   end
@@ -1434,7 +1434,7 @@ function Title_gen_wall_scene()
     local ity = math.exp(-d / 50) * 255  --- 255 - (d ^ 1.5) / 2.0,
     ity = math.clamp(0, ity, 255)
     
-    ity = math.round(ity)
+    ity = math.floor(ity)
 
     col[1] = ity
     col[2] = ity
@@ -1536,7 +1536,7 @@ function Title_gen_cave_scene()
         Title_interp_color(color_list, ity, col)
 
         gui.title_prop("color", col)
-        gui.title_draw_rect(math.round(x), math.round(y), 1, 1)
+        gui.title_draw_rect(math.floor(x), math.floor(y), 1, 1)
       end
       ::continue::
     end
@@ -1598,7 +1598,7 @@ function Title_gen_tunnel_scene()
     Title_interp_color(color_list, ity, col)
 
     gui.title_prop("color", col)
-    gui.title_draw_disc(math.round(mx - r*x_mul), math.round(my - r*y_mul), math.round(r*1.2), math.round(r))
+    gui.title_draw_disc(math.floor(mx - r*x_mul), math.floor(my - r*y_mul), math.floor(r*1.2), math.floor(r))
   end
 end
 
diff --git a/scripts/util.lua b/scripts/util.lua
index 99021552d..7e5580d2e 100644
--- a/scripts/util.lua
+++ b/scripts/util.lua
@@ -201,7 +201,7 @@ function module_param_up(module)
             if opt.increment < 1 then
               PARAM[opt.name] = value
             else
-              PARAM[opt.name] = math.round(value)
+              PARAM[opt.name] = math.floor(value)
             end
           end
         elseif opt.valuator == "button" then
@@ -348,7 +348,7 @@ end
 function table.reverse(t)
   if not t then return nil end
 
-  for x = 1, math.round(#t / 2) do
+  for x = 1, math.floor(#t / 2) do
     local y = #t - (x-1)
     -- swap 'em
     t[x], t[y] = t[y], t[x]
@@ -710,7 +710,7 @@ function rand.irange(L,H)
 end
 
 function rand.int(val)
-  return math.round(val + gui.random())
+  return math.floor(val + gui.random())
 end
 
 function rand.skew(mid, dist)
@@ -848,7 +848,7 @@ end
 -- where all the index values start at 1
 function div_mod(x, mod)
   x = x - 1
-  return 1 + math.round(x / mod), 1 + (x % mod)
+  return 1 + math.floor(x / mod), 1 + (x % mod)
 end
 
 function dir_to_delta(dir)
@@ -1247,7 +1247,7 @@ end
 
 
 function geom.box_mid(x1,y1, x2,y2)
-  return math.round((x1 + x2) / 2), math.round((y1 + y2) / 2)
+  return math.floor((x1 + x2) / 2), math.floor((y1 + y2) / 2)
 end
 
 function geom.box_size(x1,y1, x2,y2)