diff --git a/src/biome/defs/beach.rs b/src/biome/defs/beach.rs
index cb09b5b..df35d44 100644
--- a/src/biome/defs/beach.rs
+++ b/src/biome/defs/beach.rs
@@ -2,7 +2,7 @@ use crate::biome::{BiomeData, ResourceModifiers};
 
 pub const DATA: BiomeData = BiomeData {
     name: "Beach",
-    modifiers: ResourceModifiers::new(-10, -10, 10, 0, 0),
+    modifiers: ResourceModifiers::new(-10, -5, 10, 0, 5),
     has_gold_veins: false,
     land_color: Some(|t| {
         [
diff --git a/src/biome/defs/coast.rs b/src/biome/defs/coast.rs
index 9decf36..fbc0a32 100644
--- a/src/biome/defs/coast.rs
+++ b/src/biome/defs/coast.rs
@@ -2,7 +2,7 @@ use crate::biome::{BiomeData, ResourceModifiers};
 
 pub const DATA: BiomeData = BiomeData {
     name: "Coast",
-    modifiers: ResourceModifiers::new(0, 0, 15, 0, 0),
+    modifiers: ResourceModifiers::new(0, -5, 15, 0, -10),
     has_gold_veins: false,
     land_color: None,
     water_color: Some(|e, wt| {
diff --git a/src/biome/defs/deep_harbor.rs b/src/biome/defs/deep_harbor.rs
index 133c0ff..72e47da 100644
--- a/src/biome/defs/deep_harbor.rs
+++ b/src/biome/defs/deep_harbor.rs
@@ -2,7 +2,7 @@ use crate::biome::{BiomeData, ResourceModifiers};
 
 pub const DATA: BiomeData = BiomeData {
     name: "Deep Harbor",
-    modifiers: ResourceModifiers::new(0, 0, 5, 0, 0),
+    modifiers: ResourceModifiers::new(-5, -10, 20, -5, 0),
     has_gold_veins: true,
     land_color: None,
     water_color: Some(|e, wt| {
diff --git a/src/biome/defs/desert.rs b/src/biome/defs/desert.rs
index fb166c1..a684ff6 100644
--- a/src/biome/defs/desert.rs
+++ b/src/biome/defs/desert.rs
@@ -2,7 +2,7 @@ use crate::biome::{BiomeData, ResourceModifiers};
 
 pub const DATA: BiomeData = BiomeData {
     name: "Desert",
-    modifiers: ResourceModifiers::new(-20, 10, -20, 0, 0),
+    modifiers: ResourceModifiers::new(-20, 20, -25, 15, 10),
     has_gold_veins: true,
     land_color: Some(|t| {
         [
diff --git a/src/biome/defs/forest.rs b/src/biome/defs/forest.rs
index 283d83e..40c573c 100644
--- a/src/biome/defs/forest.rs
+++ b/src/biome/defs/forest.rs
@@ -2,7 +2,7 @@ use crate::biome::{BiomeData, ResourceModifiers};
 
 pub const DATA: BiomeData = BiomeData {
     name: "Forest",
-    modifiers: ResourceModifiers::new(30, 0, 10, 0, 0),
+    modifiers: ResourceModifiers::new(30, -5, 10, -20, -15),
     has_gold_veins: false,
     // Sinusoidal elevation variation gives a canopy texture.
     land_color: Some(|t| {
diff --git a/src/biome/defs/highlands.rs b/src/biome/defs/highlands.rs
index 1bdfd5d..f499dfc 100644
--- a/src/biome/defs/highlands.rs
+++ b/src/biome/defs/highlands.rs
@@ -2,7 +2,7 @@ use crate::biome::{BiomeData, ResourceModifiers};
 
 pub const DATA: BiomeData = BiomeData {
     name: "Highlands",
-    modifiers: ResourceModifiers::new(-10, 20, -5, 15, 0),
+    modifiers: ResourceModifiers::new(-15, 20, -10, 20, -15),
     has_gold_veins: true,
     land_color: Some(|t| {
         [
diff --git a/src/biome/defs/hills.rs b/src/biome/defs/hills.rs
index ed78ca9..803dac8 100644
--- a/src/biome/defs/hills.rs
+++ b/src/biome/defs/hills.rs
@@ -2,7 +2,7 @@ use crate::biome::{BiomeData, ResourceModifiers};
 
 pub const DATA: BiomeData = BiomeData {
     name: "Hills",
-    modifiers: ResourceModifiers::new(0, 25, 10, 10, 0),
+    modifiers: ResourceModifiers::new(-5, 25, 5, 5, -30),
     has_gold_veins: false,
     land_color: Some(|t| {
         [
diff --git a/src/biome/defs/mountains.rs b/src/biome/defs/mountains.rs
index 71afe48..a059e8c 100644
--- a/src/biome/defs/mountains.rs
+++ b/src/biome/defs/mountains.rs
@@ -2,7 +2,7 @@ use crate::biome::{BiomeData, ResourceModifiers};
 
 pub const DATA: BiomeData = BiomeData {
     name: "Mountains",
-    modifiers: ResourceModifiers::new(-15, 20, -15, 25, 0),
+    modifiers: ResourceModifiers::new(-20, 25, -20, 25, -10),
     has_gold_veins: true,
     land_color: Some(|t| {
         [
diff --git a/src/biome/defs/ocean.rs b/src/biome/defs/ocean.rs
index b39642a..667c2f7 100644
--- a/src/biome/defs/ocean.rs
+++ b/src/biome/defs/ocean.rs
@@ -2,7 +2,7 @@ use crate::biome::{BiomeData, ResourceModifiers};
 
 pub const DATA: BiomeData = BiomeData {
     name: "Ocean",
-    modifiers: ResourceModifiers::new(0, 0, 10, 0, 0),
+    modifiers: ResourceModifiers::new(0, 0, 15, 0, -15),
     has_gold_veins: false,
     land_color: None,
     water_color: Some(|e, wt| {
diff --git a/src/biome/defs/plains.rs b/src/biome/defs/plains.rs
index fcc0638..273349b 100644
--- a/src/biome/defs/plains.rs
+++ b/src/biome/defs/plains.rs
@@ -2,7 +2,7 @@ use crate::biome::{BiomeData, ResourceModifiers};
 
 pub const DATA: BiomeData = BiomeData {
     name: "Plains",
-    modifiers: ResourceModifiers::new(10, 0, 25, 0, 2),
+    modifiers: ResourceModifiers::new(5, -10, 25, -15, -5),
     has_gold_veins: false,
     land_color: Some(|t| {
         [
diff --git a/src/biome/defs/sacred_grove.rs b/src/biome/defs/sacred_grove.rs
index be51db7..6fe1d65 100644
--- a/src/biome/defs/sacred_grove.rs
+++ b/src/biome/defs/sacred_grove.rs
@@ -2,7 +2,7 @@ use crate::biome::{BiomeData, ResourceModifiers};
 
 pub const DATA: BiomeData = BiomeData {
     name: "Sacred Grove",
-    modifiers: ResourceModifiers::new(15, 0, 5, -20, 20),
+    modifiers: ResourceModifiers::new(10, -20, 5, -25, 30),
     has_gold_veins: false,
     land_color: Some(|t| {
         [
diff --git a/src/biome/defs/snowy_peaks.rs b/src/biome/defs/snowy_peaks.rs
index 94763b7..c81d979 100644
--- a/src/biome/defs/snowy_peaks.rs
+++ b/src/biome/defs/snowy_peaks.rs
@@ -2,7 +2,7 @@ use crate::biome::{BiomeData, ResourceModifiers};
 
 pub const DATA: BiomeData = BiomeData {
     name: "Snowy Peaks",
-    modifiers: ResourceModifiers::new(-20, 10, -25, 30, 0),
+    modifiers: ResourceModifiers::new(-15, 5, -30, 35, 5),
     has_gold_veins: true,
     land_color: Some(|t| {
         [
diff --git a/src/biome/defs/swamp.rs b/src/biome/defs/swamp.rs
index 7c6ecc0..ed1ab3e 100644
--- a/src/biome/defs/swamp.rs
+++ b/src/biome/defs/swamp.rs
@@ -2,7 +2,7 @@ use crate::biome::{BiomeData, ResourceModifiers};
 
 pub const DATA: BiomeData = BiomeData {
     name: "Swamp",
-    modifiers: ResourceModifiers::new(5, -15, 15, 0, 8),
+    modifiers: ResourceModifiers::new(5, -20, 15, -10, 10),
     has_gold_veins: false,
     land_color: Some(|t| {
         [
diff --git a/src/biome/defs/tundra.rs b/src/biome/defs/tundra.rs
index 8065a00..c57c846 100644
--- a/src/biome/defs/tundra.rs
+++ b/src/biome/defs/tundra.rs
@@ -2,7 +2,7 @@ use crate::biome::{BiomeData, ResourceModifiers};
 
 pub const DATA: BiomeData = BiomeData {
     name: "Tundra",
-    modifiers: ResourceModifiers::new(-15, 5, -15, 20, 5),
+    modifiers: ResourceModifiers::new(-15, 5, -20, 25, 5),
     has_gold_veins: false,
     land_color: Some(|t| {
         [
diff --git a/src/biome/defs/valley.rs b/src/biome/defs/valley.rs
index e3b05a4..1b2c8f5 100644
--- a/src/biome/defs/valley.rs
+++ b/src/biome/defs/valley.rs
@@ -2,7 +2,7 @@ use crate::biome::{BiomeData, ResourceModifiers};
 
 pub const DATA: BiomeData = BiomeData {
     name: "Valley",
-    modifiers: ResourceModifiers::new(15, 0, 20, 0, 0),
+    modifiers: ResourceModifiers::new(15, -5, 20, -15, -15),
     has_gold_veins: true,
     land_color: Some(|t| {
         [