diff --git a/binaries/data/mods/public/maps/random/archipelago.js b/binaries/data/mods/public/maps/random/archipelago.js
index deb563edb1..5646f30d77 100644
--- a/binaries/data/mods/public/maps/random/archipelago.js
+++ b/binaries/data/mods/public/maps/random/archipelago.js
@@ -316,7 +316,7 @@ RMS.SetProgress(65);
 // create decoration
 var planetm = 1;
 
-if (random_terrain==7)
+if (random_terrain == g_BiomeTropic)
 	planetm = 8;
 
 createDecoration
diff --git a/binaries/data/mods/public/maps/random/canyon.js b/binaries/data/mods/public/maps/random/canyon.js
index ba3fb9dcc1..4b5f7f6e70 100644
--- a/binaries/data/mods/public/maps/random/canyon.js
+++ b/binaries/data/mods/public/maps/random/canyon.js
@@ -454,7 +454,7 @@ RMS.SetProgress(65);
 // create decoration
 var planetm = 1;
 
-if (random_terrain==7)
+if (random_terrain == g_BiomeTropic)
 	planetm = 8;
 
 createDecoration
diff --git a/binaries/data/mods/public/maps/random/continent.js b/binaries/data/mods/public/maps/random/continent.js
index 061bc7064d..a7401b381e 100644
--- a/binaries/data/mods/public/maps/random/continent.js
+++ b/binaries/data/mods/public/maps/random/continent.js
@@ -317,7 +317,7 @@ RMS.SetProgress(65);
 // create decoration
 var planetm = 1;
 
-if (random_terrain==7)
+if (random_terrain == g_BiomeTropic)
 	planetm = 8;
 
 createDecoration
diff --git a/binaries/data/mods/public/maps/random/flood.js b/binaries/data/mods/public/maps/random/flood.js
index e82128b135..65027c72d5 100644
--- a/binaries/data/mods/public/maps/random/flood.js
+++ b/binaries/data/mods/public/maps/random/flood.js
@@ -1,7 +1,6 @@
 RMS.LoadLibrary("rmgen");
 
-//Random terrain textures, exclude african biome
-let random_terrain = randomizeBiome([6]);
+let random_terrain = randomizeBiome([g_BiomeSavanna]);
 
 const tMainTerrain = rBiomeT1();
 const tForestFloor1 = rBiomeT2();
@@ -18,7 +17,7 @@ const tWater = rBiomeT15();
 let tHill = rBiomeT8();
 let tDirt = rBiomeT9();
 
-if (random_terrain == 1)
+if (random_terrain == g_BiomeTemperate)
 {
 	tDirt = ["medit_shrubs_a", "grass_field"];
 	tHill = ["grass_field", "peat_temp"];
@@ -333,7 +332,7 @@ RMS.SetProgress(65);
 
 log("Creating dirt patches...");
 let sizes = [scaleByMapSize(3, 6), scaleByMapSize(5, 10), scaleByMapSize(8, 21)];
-let numb = random_terrain == 6 ? 3 : 1;
+let numb = random_terrain == g_BiomeSavanna ? 3 : 1;
 
 for (let i = 0; i < sizes.length; ++i)
 {
@@ -394,7 +393,7 @@ log("Creating more straggeler trees...");
 createStragglerTrees(types, avoidClasses(clWater, 5, clForest, 7, clMountain, 1, clPlayer, 30, clMetal, 3, clRock, 3));
 
 log("Creating decoration...");
-let planetm = random_terrain == 7 ? 8 : 1;
+let planetm = random_terrain == g_BiomeTropic ? 8 : 1;
 createDecoration
 (
 	[
diff --git a/binaries/data/mods/public/maps/random/gear.js b/binaries/data/mods/public/maps/random/gear.js
index 2b6c4659ca..1b40b0a47a 100644
--- a/binaries/data/mods/public/maps/random/gear.js
+++ b/binaries/data/mods/public/maps/random/gear.js
@@ -474,7 +474,7 @@ RMS.SetProgress(65);
 // create decoration
 var planetm = 1;
 
-if (random_terrain==7)
+if (random_terrain == g_BiomeTropic)
 	planetm = 8;
 
 createDecoration
diff --git a/binaries/data/mods/public/maps/random/hells_pass.js b/binaries/data/mods/public/maps/random/hells_pass.js
index c7b7afbfca..5b0afb080f 100644
--- a/binaries/data/mods/public/maps/random/hells_pass.js
+++ b/binaries/data/mods/public/maps/random/hells_pass.js
@@ -220,13 +220,13 @@ function placeBarriers()
 {
 	var spineTerrain = g_Terrains.dirt;
 
-	if (g_MapInfo.biome == 2)
+	if (g_MapInfo.biome == g_BiomeSnowy)
 		spineTerrain = g_Terrains.tier1Terrain;
 
-	if (g_MapInfo.biome == 4 || g_MapInfo.biome == 6)
+	if (g_MapInfo.biome == g_BiomeAlpine || g_MapInfo.biome == g_BiomeSavanna)
 		spineTerrain = g_Terrains.tier2Terrain;
 
-	if (g_MapInfo.biome == 8)
+	if (g_MapInfo.biome == g_BiomeAutumn)
 		spineTerrain = g_Terrains.tier4Terrain;
 
 	// create mountain ranges
diff --git a/binaries/data/mods/public/maps/random/island_stronghold.js b/binaries/data/mods/public/maps/random/island_stronghold.js
index 9e80dd488a..323a02b457 100644
--- a/binaries/data/mods/public/maps/random/island_stronghold.js
+++ b/binaries/data/mods/public/maps/random/island_stronghold.js
@@ -33,8 +33,7 @@ const g_InitialMines = 1;
 const g_InitialMineDistance = 14;
 const g_InitialTrees = 50;
 
-// Random terrain textures, exclude african biome
-let random_terrain = randomizeBiome([6]);
+let random_terrain = randomizeBiome([g_BiomeSavanna]);
 
 const tMainTerrain = rBiomeT1();
 const tForestFloor1 = rBiomeT2();
@@ -446,7 +445,7 @@ createFood(
 	[avoidClasses(clForest, 0, clPlayer, 15, clHill, 1, clFood, 4, clRock, 4, clMetal, 4), stayClasses(clLand, 2)]
 );
 
-if (random_terrain == 3)
+if (random_terrain == g_BiomeDesert)
 {
 	log("Creating obelisks");
 	let group = new SimpleGroup(
@@ -462,7 +461,7 @@ if (random_terrain == 3)
 
 log("Creating dirt patches...");
 let sizes = [scaleByMapSize(3, 6), scaleByMapSize(5, 10), scaleByMapSize(8, 21)];
-let numb = random_terrain == 6 ? 3 : 1;
+let numb = random_terrain == g_BiomeSavanna ? 3 : 1;
 
 for (let i = 0; i < sizes.length; ++i)
 {
diff --git a/binaries/data/mods/public/maps/random/islands.js b/binaries/data/mods/public/maps/random/islands.js
index f8e00190e6..f29e8b6b55 100644
--- a/binaries/data/mods/public/maps/random/islands.js
+++ b/binaries/data/mods/public/maps/random/islands.js
@@ -350,13 +350,13 @@ createAreas(
 
 
 // calculate desired number of trees for map (based on size)
-if (random_terrain == 6)
+if (random_terrain == g_BiomeSavanna)
 {
 	var MIN_TREES = 200;
 	var MAX_TREES = 1250;
 	var P_FOREST = 0;
 }
-else if (random_terrain == 7)
+else if (random_terrain == g_BiomeTropic)
 {
 	var MIN_TREES = 1000;
 	var MAX_TREES = 6000;
@@ -379,7 +379,7 @@ var types = [
 	[[tForestFloor1, tMainTerrain, pForest2], [tForestFloor1, pForest2]]
 ];	// some variation
 
-if (random_terrain != 6)
+if (random_terrain != g_BiomeSavanna)
 {
 	var size = numForest / (scaleByMapSize(3,6) * numPlayers);
 	var num = floor(size / types.length);
@@ -404,7 +404,7 @@ RMS.SetProgress(50);
 log("Creating dirt patches...");
 var sizes = [scaleByMapSize(3, 6), scaleByMapSize(5, 10), scaleByMapSize(8, 21)];
 var numb = 1;
-if (random_terrain == 6)
+if (random_terrain == g_BiomeSavanna)
 	numb = 3
 for (var i = 0; i < sizes.length; i++)
 {
@@ -556,10 +556,9 @@ for (var i = 0; i < types.length; ++i)
 }
 
 var planetm = 1;
-if (random_terrain==7)
-{
+if (random_terrain == g_BiomeTropic)
 	planetm = 8;
-}
+
 //create small grass tufts
 log("Creating small grass tufts...");
 group = new SimpleGroup(
diff --git a/binaries/data/mods/public/maps/random/lake.js b/binaries/data/mods/public/maps/random/lake.js
index 30b45cd47e..142d972004 100644
--- a/binaries/data/mods/public/maps/random/lake.js
+++ b/binaries/data/mods/public/maps/random/lake.js
@@ -328,7 +328,7 @@ RMS.SetProgress(65);
 // create decoration
 var planetm = 1;
 
-if (random_terrain==7)
+if (random_terrain == g_BiomeTropic)
 	planetm = 8;
 
 createDecoration
diff --git a/binaries/data/mods/public/maps/random/lions_den.js b/binaries/data/mods/public/maps/random/lions_den.js
index 693e147c02..47b3b6dd7c 100644
--- a/binaries/data/mods/public/maps/random/lions_den.js
+++ b/binaries/data/mods/public/maps/random/lions_den.js
@@ -380,34 +380,34 @@ function createSunkenTerrain(players)
 	var lower = g_Terrains.tier2Terrain;
 	var road = g_Terrains.road;
 
-	if (g_MapInfo.biome == 2)
+	if (g_MapInfo.biome == g_BiomeSnowy)
 	{
 		middle = g_Terrains.tier2Terrain;
 		lower = g_Terrains.tier1Terrain;
 	}
 
-	if (g_MapInfo.biome == 4)
+	if (g_MapInfo.biome == g_BiomeAlpine)
 	{
 		middle = g_Terrains.shore;
 		lower = g_Terrains.tier4Terrain;
 	}
 
-	if (g_MapInfo.biome == 5)
+	if (g_MapInfo.biome == g_BiomeMediterranean)
 	{
 		middle = g_Terrains.tier1Terrain;
 		lower = g_Terrains.forestFloor1;
 	}
 
-	if (g_MapInfo.biome == 6)
+	if (g_MapInfo.biome == g_BiomeSavanna)
 	{
 		middle = g_Terrains.tier2Terrain;
 		lower = g_Terrains.tier4Terrain;
 	}
 
-	if (g_MapInfo.biome == 7 || g_MapInfo.biome == 8)
+	if (g_MapInfo.biome == g_BiomeTropic || g_MapInfo.biome == g_BiomeAutumn)
 		road = g_Terrains.roadWild;
 
-	if (g_MapInfo.biome == 8)
+	if (g_MapInfo.biome == g_BiomeAutumn)
 		middle = g_Terrains.shore;
 
 	var expSize = g_MapInfo.mapArea * 0.015 / (g_MapInfo.numPlayers / 4);
diff --git a/binaries/data/mods/public/maps/random/mainland.js b/binaries/data/mods/public/maps/random/mainland.js
index 303f056786..6df7741626 100644
--- a/binaries/data/mods/public/maps/random/mainland.js
+++ b/binaries/data/mods/public/maps/random/mainland.js
@@ -275,7 +275,7 @@ RMS.SetProgress(65);
 // create decoration
 var planetm = 1;
 
-if (random_terrain==7)
+if (random_terrain == g_BiomeTropic)
 	planetm = 8;
 
 createDecoration
diff --git a/binaries/data/mods/public/maps/random/migration.js b/binaries/data/mods/public/maps/random/migration.js
index d017f8a74a..48117944fa 100644
--- a/binaries/data/mods/public/maps/random/migration.js
+++ b/binaries/data/mods/public/maps/random/migration.js
@@ -295,13 +295,13 @@ createAreas(
 );
 
 // calculate desired number of trees for map (based on size)
-if (random_terrain == 6)
+if (random_terrain == g_BiomeSavanna)
 {
 	var MIN_TREES = 200;
 	var MAX_TREES = 1250;
 	var P_FOREST = 0.02;
 }
-else if (random_terrain == 7)
+else if (random_terrain == g_BiomeTropic)
 {
 	var MIN_TREES = 1000;
 	var MAX_TREES = 6000;
diff --git a/binaries/data/mods/public/maps/random/rivers.js b/binaries/data/mods/public/maps/random/rivers.js
index 2e3402c356..a5a8293b7c 100644
--- a/binaries/data/mods/public/maps/random/rivers.js
+++ b/binaries/data/mods/public/maps/random/rivers.js
@@ -18,7 +18,7 @@ const tTier4Terrain = rBiomeT12();
 const tShoreBlend = rBiomeT13();
 var tShore = rBiomeT14();
 var tWater = rBiomeT15();
-if (random_terrain == 7)
+if (random_terrain == g_BiomeTropic)
 {
 	tShore = "tropic_dirt_b_plants";
 	tWater = "tropic_dirt_b";
@@ -458,7 +458,7 @@ RMS.SetProgress(65);
 // create decoration
 var planetm = 1;
 
-if (random_terrain==7)
+if (random_terrain == g_BiomeTropic)
 	planetm = 8;
 
 createDecoration
diff --git a/binaries/data/mods/public/maps/random/rmgen/gaia.js b/binaries/data/mods/public/maps/random/rmgen/gaia.js
index f2cd1060f5..5b7debd7ba 100644
--- a/binaries/data/mods/public/maps/random/rmgen/gaia.js
+++ b/binaries/data/mods/public/maps/random/rmgen/gaia.js
@@ -320,7 +320,7 @@ function addDecoration(constraint, size, deviation, fill)
 	];
 
 	var baseCount = 1;
-	if (g_MapInfo.biome == 7)
+	if (g_MapInfo.biome == g_BiomeTropic)
 		baseCount = 8;
 
 	var counts = [
@@ -437,13 +437,13 @@ function addLakes(constraint, size, deviation, fill)
 {
 	var lakeTile = g_Terrains.water;
 
-	if (g_MapInfo.biome == 0 || g_MapInfo.biome == 1 || g_MapInfo.biome == 7)
+	if (g_MapInfo.biome == g_BiomeTemperate || g_MapInfo.biome == g_BiomeTropic)
 		lakeTile = g_Terrains.dirt;
 
-	if (g_MapInfo.biome == 5)
+	if (g_MapInfo.biome == g_BiomeMediterranean)
 		lakeTile = g_Terrains.tier2Terrain;
 
-	if (g_MapInfo.biome == 8)
+	if (g_MapInfo.biome == g_BiomeAutumn)
 		lakeTile = g_Terrains.shore;
 
 	addElevation(constraint, {
@@ -556,13 +556,13 @@ function addPlateaus(constraint, size, deviation, fill)
 {
 	var plateauTile = g_Terrains.dirt;
 
-	if (g_MapInfo.biome == 2)
+	if (g_MapInfo.biome == g_BiomeSnowy)
 		plateauTile = g_Terrains.tier1Terrain;
 
-	if (g_MapInfo.biome == 4 || g_MapInfo.biome == 6)
+	if (g_MapInfo.biome == g_BiomeAlpine || g_MapInfo.biome == g_BiomeSavanna)
 		plateauTile = g_Terrains.tier2Terrain;
 
-	if (g_MapInfo.biome == 8)
+	if (g_MapInfo.biome == g_BiomeAutumn)
 		plateauTile = g_Terrains.tier4Terrain;
 
 	addElevation(constraint, {
@@ -732,31 +732,25 @@ function addValleys(constraint, size, deviation, fill)
 	var valleySlope = g_Terrains.tier1Terrain;
 	var valleyFloor = g_Terrains.tier4Terrain;
 
-	if (g_MapInfo.biome == 0)
-	{
-		valleySlope = g_Terrains.dirt;
-		valleyFloor = g_Terrains.tier2Terrain;
-	}
-
-	if (g_MapInfo.biome == 3)
+	if (g_MapInfo.biome == g_BiomeDesert)
 	{
 		valleySlope = g_Terrains.tier3Terrain;
 		valleyFloor = g_Terrains.dirt;
 	}
 
-	if (g_MapInfo.biome == 5)
+	if (g_MapInfo.biome == g_BiomeMediterranean)
 	{
 		valleySlope = g_Terrains.tier2Terrain;
 		valleyFloor = g_Terrains.dirt;
 	}
 
-	if (g_MapInfo.biome == 4 || g_MapInfo.biome == 6)
+	if (g_MapInfo.biome == g_BiomeAlpine || g_MapInfo.biome == g_BiomeSavanna)
 		valleyFloor = g_Terrains.tier2Terrain;
 
-	if (g_MapInfo.biome == 7)
+	if (g_MapInfo.biome == g_BiomeTropic)
 		valleySlope = g_Terrains.dirt;
 
-	if (g_MapInfo.biome == 8)
+	if (g_MapInfo.biome == g_BiomeAutumn)
 		valleyFloor = g_Terrains.tier3Terrain;
 
 	addElevation(constraint, {
@@ -856,7 +850,7 @@ function addForests(constraint, size, deviation, fill)
 	fill = fill || 1;
 
 	// No forests for the african biome
-	if (g_MapInfo.biome == 6)
+	if (g_MapInfo.biome == g_BiomeSavanna)
 		return;
 
 	var types = [
@@ -947,7 +941,7 @@ function addStragglerTrees(constraint, size, deviation, fill)
 	fill = fill || 1;
 
 	// Ensure minimum distribution on african biome
-	if (g_MapInfo.biome == 6)
+	if (g_MapInfo.biome == g_BiomeSavanna)
 	{
 		fill = Math.max(fill, 2);
 		size = Math.max(size, 1);
@@ -969,7 +963,7 @@ function addStragglerTrees(constraint, size, deviation, fill)
 	var maxDist = 5 * offset;
 
 	// More trees for the african biome
-	if (g_MapInfo.biome == 6)
+	if (g_MapInfo.biome == g_BiomeSavanna)
 	{
 		min = 3 * offset;
 		max = 5 * offset;
@@ -982,7 +976,7 @@ function addStragglerTrees(constraint, size, deviation, fill)
 		var treesMax = max;
 
 		// Don't clump fruit trees
-		if (i == 2 && (g_MapInfo.biome == 3 || g_MapInfo.biome == 5))
+		if (i == 2 && (g_MapInfo.biome == g_BiomeDesert || g_MapInfo.biome == g_BiomeMediterranean))
 			treesMax = 1;
 
 		min = Math.min(min, treesMax);
diff --git a/binaries/data/mods/public/maps/random/rmgen/randombiome.js b/binaries/data/mods/public/maps/random/rmgen/randombiome.js
index 4b219fae3c..53d6d8cb79 100644
--- a/binaries/data/mods/public/maps/random/rmgen/randombiome.js
+++ b/binaries/data/mods/public/maps/random/rmgen/randombiome.js
@@ -1,3 +1,12 @@
+const g_BiomeTemperate = 1;
+const g_BiomeSnowy = 2;
+const g_BiomeDesert = 3;
+const g_BiomeAlpine = 4;
+const g_BiomeMediterranean = 5;
+const g_BiomeSavanna = 6;
+const g_BiomeTropic = 7;
+const g_BiomeAutumn = 8;
+
 var biomeID = 1;
 var rbt1 = ["temp_grass_long_b"];
 var rbt2 = "temp_forestfloor_pine";
@@ -74,8 +83,7 @@ function setBiome(biomeIndex)
 
 	biomeID = biomeIndex;
 
-	//temperate
-	if (biomeID == 1)
+	if (biomeID == g_BiomeTemperate)
 	{
 		// temperate ocean blue, a bit too deep and saturated perhaps but it looks nicer.
 		// this assumes ocean settings, maps that aren't oceans should reset.
@@ -179,8 +187,7 @@ function setBiome(biomeIndex)
 		rba8 = "actor|props/flora/bush_medit_sm.xml";
 		rba9 = "actor|flora/trees/oak.xml";
 	}
-	//snowy
-	else if (biomeID == 2)
+	else if (biomeID == g_BiomeSnowy)
 	{
 		setSunColor(0.550, 0.601, 0.644);				// a little darker
 		// Water is a semi-deep blue, fairly wavy, fairly murky for an ocean.
@@ -237,8 +244,7 @@ function setBiome(biomeIndex)
 		setPPSaturation(0.37);
 		setPPEffect("hdr");
 	}
-	//desert
-	else if (biomeID == 3)
+	else if (biomeID == g_BiomeDesert)
 	{
 		setSunColor(0.733, 0.746, 0.574);	
 
@@ -315,8 +321,7 @@ function setBiome(biomeIndex)
 		rba8 = "actor|props/flora/bush_desert_dry_a.xml";
 		rba9 = "actor|flora/trees/palm_date.xml";
 	}
-	//alpine
-	else if (biomeID == 4)
+	else if (biomeID == g_BiomeAlpine)
 	{
 		// simulates an alpine lake, fairly deep.
 		// this is not intended for a clear running river, or even an ocean.
@@ -375,8 +380,7 @@ function setBiome(biomeIndex)
 		rba8 = "actor|props/flora/bush_desert_a.xml";
 		rba9 = "actor|flora/trees/pine.xml";
 	}
-	//medit
-	else if (biomeID == 5)
+	else if (biomeID == g_BiomeMediterranean)
 	{
 		// Guess what, this is based on the colors of the mediterranean sea.
 		setWaterColor(0.024,0.212,0.024);
@@ -470,8 +474,7 @@ function setBiome(biomeIndex)
 		rba8 = "actor|props/flora/bush_medit_sm.xml";
 		rba9 = "actor|flora/trees/palm_cretan_date.xml";
 	}
-	//savanah
-	else if (biomeID == 6)
+	else if (biomeID == g_BiomeSavanna)
 	{
 		// Using the Malawi as a reference, in parts where it's not too murky from a river nearby.
 		setWaterColor(0.055,0.176,0.431);
@@ -539,8 +542,7 @@ function setBiome(biomeIndex)
 		rba8 = "actor|props/flora/bush_dry_a.xml";
 		rba9 = "actor|flora/trees/baobab.xml";
 	}
-	//tropic
-	else if (biomeID == 7)
+	else if (biomeID == g_BiomeTropic)
 	{
 		
 		// Bora-Bora ish. Quite transparent, not wavy.
@@ -600,8 +602,7 @@ function setBiome(biomeIndex)
 		rba8 = "actor|props/flora/plant_tropic_large.xml";
 		rba9 = "actor|flora/trees/tree_tropic.xml";
 	}
-	//autumn
-	else if (biomeID == 8)
+	else if (biomeID == g_BiomeAutumn)
 	{
 		// basically temperate with a reddish twist in the reflection and the tint. Also less wavy.
 		// this assumes ocean settings, maps that aren't oceans should reset.
diff --git a/binaries/data/mods/public/maps/random/rmgen/utilityfunctions.js b/binaries/data/mods/public/maps/random/rmgen/utilityfunctions.js
index 8240962d4a..f94336fce2 100644
--- a/binaries/data/mods/public/maps/random/rmgen/utilityfunctions.js
+++ b/binaries/data/mods/public/maps/random/rmgen/utilityfunctions.js
@@ -95,13 +95,13 @@ function createForests(terrainset, constraint, tileclass, numMultiplier, biomeID
 	var tF1 = terrainset[3]
 	var tF2 = terrainset[4]
 
-	if (biomeID == 6)
+	if (biomeID == g_BiomeSavanna)
 	{
 		var MIN_TREES = 200 * numMultiplier;
 		var MAX_TREES = 1250 * numMultiplier;
 		var P_FOREST = 0;
 	}
-	else if (biomeID == 7)
+	else if (biomeID == g_BiomeTropic)
 	{
 		var MIN_TREES = 1000 * numMultiplier;
 		var MAX_TREES = 6000 * numMultiplier;
@@ -124,7 +124,7 @@ function createForests(terrainset, constraint, tileclass, numMultiplier, biomeID
 		[[tFF1, tM, tF2], [tFF1, tF2]]
 	];	// some variation
 
-	if (biomeID != 6)
+	if (biomeID != g_BiomeSavanna)
 	{
 		var size = numForest / (scaleByMapSize(3,6) * numPlayers);
 		var num = floor(size / types.length);
diff --git a/binaries/data/mods/public/maps/random/snowflake_searocks.js b/binaries/data/mods/public/maps/random/snowflake_searocks.js
index 21f40c25bb..be86559f24 100644
--- a/binaries/data/mods/public/maps/random/snowflake_searocks.js
+++ b/binaries/data/mods/public/maps/random/snowflake_searocks.js
@@ -1687,13 +1687,13 @@ for (var ix = 0; ix < mapSize; ix++)
 }
 
 // calculate desired number of trees for map (based on size)
-if (random_terrain == 6)
+if (random_terrain == g_BiomeSavanna)
 {
 	var MIN_TREES = 200;
 	var MAX_TREES = 1250;
 	var P_FOREST = 0.02;
 }
-else if (random_terrain == 7)
+else if (random_terrain == g_BiomeTropic)
 {
 	var MIN_TREES = 1000;
 	var MAX_TREES = 6000;
@@ -1716,14 +1716,11 @@ var types = [
 	[[tForestFloor1, tMainTerrain, pForest2], [tForestFloor1, pForest2]]
 ];	// some variation
 
-if (random_terrain == 6)
-{
+if (random_terrain == g_BiomeSavanna)
 	var size = numForest / (0.5 * scaleByMapSize(2,8) * numPlayers);
-}
-	else
-{
+else
 	var size = numForest / (scaleByMapSize(2,8) * numPlayers);
-}
+
 var num = floor(size / types.length);
 for (var i = 0; i < types.length; ++i)
 {
@@ -1882,10 +1879,9 @@ for (var i = 0; i < types.length; ++i)
 }
 
 var planetm = 1;
-if (random_terrain==7)
-{
+if (random_terrain == g_BiomeTropic)
 	planetm = 8;
-}
+
 //create small grass tufts
 log("Creating small grass tufts...");
 group = new SimpleGroup(
diff --git a/binaries/data/mods/public/maps/random/survivalofthefittest.js b/binaries/data/mods/public/maps/random/survivalofthefittest.js
index 1e3a09221e..d7da0a96ee 100644
--- a/binaries/data/mods/public/maps/random/survivalofthefittest.js
+++ b/binaries/data/mods/public/maps/random/survivalofthefittest.js
@@ -262,7 +262,7 @@ createPatches(
 // create decoration
 var planetm = 1;
 
-if (random_terrain==7)
+if (random_terrain == g_BiomeTropic)
 	planetm = 8;
 
 createDecoration
diff --git a/binaries/data/mods/public/maps/random/unknown.js b/binaries/data/mods/public/maps/random/unknown.js
index 940cd6b3ee..dda1ff6c93 100644
--- a/binaries/data/mods/public/maps/random/unknown.js
+++ b/binaries/data/mods/public/maps/random/unknown.js
@@ -1804,13 +1804,13 @@ createAreas(
 
 var multiplier = sqrt(randFloat(0.5,1.2)*randFloat(0.5,1.2));
 // calculate desired number of trees for map (based on size)
-if (random_terrain == 6)
+if (random_terrain == g_BiomeSavanna)
 {
 	var MIN_TREES = floor(200*multiplier);
 	var MAX_TREES = floor(1250*multiplier);
 	var P_FOREST = randFloat(0.02, 0.05);
 }
-else if (random_terrain == 7)
+else if (random_terrain == g_BiomeTropic)
 {
 	var MIN_TREES = floor(1000*multiplier);
 	var MAX_TREES = floor(6000*multiplier);
@@ -1833,14 +1833,11 @@ var types = [
 	[[tForestFloor1, tMainTerrain, pForest2], [tForestFloor1, pForest2]]
 ];	// some variation
 
-if (random_terrain == 6)
-{
+if (random_terrain == g_BiomeSavanna)
 	var size = numForest / (0.5 * scaleByMapSize(2,8) * numPlayers);
-}
 else
-{
 	var size = numForest / (scaleByMapSize(2,8) * numPlayers);
-}
+
 var num = floor(size / types.length);
 for (var i = 0; i < types.length; ++i)
 {
@@ -1862,7 +1859,7 @@ RMS.SetProgress(50);
 log("Creating dirt patches...");
 var sizes = [scaleByMapSize(3, 48), scaleByMapSize(5, 84), scaleByMapSize(8, 128)];
 var numb = 1;
-if (random_terrain == 6)
+if (random_terrain == g_BiomeSavanna)
 	numb = 3
 for (var i = 0; i < sizes.length; i++)
 {
@@ -2014,10 +2011,9 @@ for (var i = 0; i < types.length; ++i)
 }
 
 var planetm = 1;
-if (random_terrain==7)
-{
+if (random_terrain == g_BiomeTropic)
 	planetm = 8;
-}
+
 //create small grass tufts
 log("Creating small grass tufts...");
 group = new SimpleGroup(
diff --git a/binaries/data/mods/public/maps/random/unknown_land.js b/binaries/data/mods/public/maps/random/unknown_land.js
index e66a9fbeb7..9c4ce84c48 100644
--- a/binaries/data/mods/public/maps/random/unknown_land.js
+++ b/binaries/data/mods/public/maps/random/unknown_land.js
@@ -1574,13 +1574,13 @@ createAreas(
 
 var multiplier = sqrt(randFloat(0.5,1.2)*randFloat(0.5,1.2));
 // calculate desired number of trees for map (based on size)
-if (random_terrain == 6)
+if (random_terrain == g_BiomeSavanna)
 {
 	var MIN_TREES = floor(200*multiplier);
 	var MAX_TREES = floor(1250*multiplier);
 	var P_FOREST = 0;
 }
-else if (random_terrain == 7)
+else if (random_terrain == g_BiomeTropic)
 {
 	var MIN_TREES = floor(1000*multiplier);
 	var MAX_TREES = floor(6000*multiplier);
@@ -1603,7 +1603,7 @@ var types = [
 	[[tForestFloor1, tMainTerrain, pForest2], [tForestFloor1, pForest2]]
 ];	// some variation
 
-if (random_terrain != 6)
+if (random_terrain != g_BiomeSavanna)
 {
 	var size = numForest / (scaleByMapSize(3,6) * numPlayers);
 	var num = floor(size / types.length);
@@ -1780,10 +1780,9 @@ for (var i = 0; i < types.length; ++i)
 }
 
 var planetm = 1;
-if (random_terrain==7)
-{
+if (random_terrain == g_BiomeTropic)
 	planetm = 8;
-}
+
 //create small grass tufts
 log("Creating small grass tufts...");
 group = new SimpleGroup(