diff --git a/core/src/mindustry/core/World.java b/core/src/mindustry/core/World.java
index c08c186b2b..7dacad6e59 100644
--- a/core/src/mindustry/core/World.java
+++ b/core/src/mindustry/core/World.java
@@ -320,6 +320,7 @@ public class World{
 
         state.rules.cloudColor = sector.planet.landCloudColor;
         state.rules.env = sector.planet.defaultEnv;
+        state.rules.planet = sector.planet;
         state.rules.hiddenBuildItems.clear();
         state.rules.hiddenBuildItems.addAll(sector.planet.hiddenItems);
         sector.planet.applyRules(state.rules);
diff --git a/core/src/mindustry/game/Rules.java b/core/src/mindustry/game/Rules.java
index 177021f1cb..ede6161f49 100644
--- a/core/src/mindustry/game/Rules.java
+++ b/core/src/mindustry/game/Rules.java
@@ -191,6 +191,8 @@ public class Rules{
     public float backgroundOffsetX = 0.1f, backgroundOffsetY = 0.1f;
     /** Parameters for planet rendered in the background. Cannot be changed once a map is loaded. */
     public @Nullable PlanetParams planetBackground;
+    /** Rules from this planet are applied. If it's {@code sun}, mixed tech is enabled. */
+    public Planet planet = Planets.serpulo;
 
     /** Copies this ruleset exactly. Not efficient at all, do not use often. */
     public Rules copy(){
diff --git a/core/src/mindustry/type/Planet.java b/core/src/mindustry/type/Planet.java
index e63db3a4e8..68c07a239b 100644
--- a/core/src/mindustry/type/Planet.java
+++ b/core/src/mindustry/type/Planet.java
@@ -211,6 +211,7 @@ public class Planet extends UnlockableContent{
         rules.attributes.clear();
         rules.attributes.add(defaultAttributes);
         rules.env = defaultEnv;
+        rules.planet = this;
         rules.hiddenBuildItems.clear();
         rules.hiddenBuildItems.addAll(hiddenItems);
     }
diff --git a/core/src/mindustry/ui/dialogs/CustomRulesDialog.java b/core/src/mindustry/ui/dialogs/CustomRulesDialog.java
index f1f574f954..1708005773 100644
--- a/core/src/mindustry/ui/dialogs/CustomRulesDialog.java
+++ b/core/src/mindustry/ui/dialogs/CustomRulesDialog.java
@@ -249,15 +249,14 @@ public class CustomRulesDialog extends BaseDialog{
 
             t.defaults().size(140f, 50f);
 
-            //TODO dynamic selection of planets
-            for(Planet planet : new Planet[]{Planets.serpulo, Planets.erekir}){
+            for(Planet planet : content.planets().select(p -> p.accessible && p.visible && p.isLandable())){
                 t.button(planet.localizedName, style, () -> {
-                    rules.env = planet.defaultEnv;
-                    rules.attributes.clear();
-                    rules.attributes.add(planet.defaultAttributes);
-                    rules.hiddenBuildItems.clear();
-                    rules.hiddenBuildItems.addAll(planet.hiddenItems);
-                }).group(group).checked(b -> rules.env == planet.defaultEnv);
+                    planet.applyRules(rules);
+                }).group(group).checked(b -> rules.planet == planet);
+
+                if(t.getChildren().size % 3 == 0){
+                    t.row();
+                }
             }
 
             t.button("@rules.anyenv", style, () -> {
@@ -267,8 +266,9 @@ public class CustomRulesDialog extends BaseDialog{
                 }else{
                     rules.env = Vars.defaultEnv;
                     rules.hiddenBuildItems.clear();
+                    rules.planet = Planets.sun;
                 }
-            }).group(group).checked(b -> rules.hiddenBuildItems.size == 0);
+            }).group(group).checked(b -> rules.planet == Planets.sun);
         }).left().fill(false).expand(false, false).row();
 
         title("@rules.title.teams");