Index: ps/trunk/binaries/data/mods/public/simulation/ai/petra/baseManager.js
===================================================================
--- ps/trunk/binaries/data/mods/public/simulation/ai/petra/baseManager.js
+++ ps/trunk/binaries/data/mods/public/simulation/ai/petra/baseManager.js
@@ -496,8 +496,9 @@
 						{
 							// No good dropsite, try to build a new base if no base already planned,
 							// and if not possible, be less strict on dropsite quality
-							if (!gameState.ai.HQ.buildNewBase(gameState, queues, type) && newDP.quality > Math.min(25, 50*0.15/ratio) &&
-								gameState.ai.HQ.canBuild(gameState, "structures/{civ}_storehouse"))
+							if ((!gameState.ai.HQ.canExpand || !gameState.ai.HQ.buildNewBase(gameState, queues, type)) &&
+							    newDP.quality > Math.min(25, 50*0.15/ratio) &&
+							    gameState.ai.HQ.canBuild(gameState, "structures/{civ}_storehouse"))
 								queues.dropsites.addPlan(new m.ConstructionPlan(gameState, "structures/{civ}_storehouse", { "base": this.ID, "type": type }, newDP.pos));
 						}
 					}
Index: ps/trunk/binaries/data/mods/public/simulation/ai/petra/headquarters.js
===================================================================
--- ps/trunk/binaries/data/mods/public/simulation/ai/petra/headquarters.js
+++ ps/trunk/binaries/data/mods/public/simulation/ai/petra/headquarters.js
@@ -2247,7 +2247,7 @@
 	}
 
 	if (this.numActiveBase() < 1 ||
-		(this.Config.difficulty > 0 && gameState.ai.playedTurn % 10 == 7 && gameState.currentPhase() > 1))
+		(this.canExpand && gameState.ai.playedTurn % 10 == 7 && gameState.currentPhase() > 1))
 		this.checkBaseExpansion(gameState, queues);
 
 	if (gameState.currentPhase() > 1)
@@ -2316,6 +2316,7 @@
 		"needCorral": this.needCorral,
 		"needFarm": this.needFarm,
 		"needFish": this.needFish,
+		"canExpand": this.canExpand,
 		"canBuildUnits": this.canBuildUnits,
 		"navalMap": this.navalMap,
 		"landRegions": this.landRegions,
Index: ps/trunk/binaries/data/mods/public/simulation/ai/petra/startingStrategy.js
===================================================================
--- ps/trunk/binaries/data/mods/public/simulation/ai/petra/startingStrategy.js
+++ ps/trunk/binaries/data/mods/public/simulation/ai/petra/startingStrategy.js
@@ -36,6 +36,9 @@
 	// Assign entities and resources in the different bases
 	this.assignStartingEntities(gameState);
 
+
+	// Sandbox difficulty should not try to expand
+	this.canExpand = this.Config.difficulty != 0;
 	// If no base yet, check if we can construct one. If not, dispatch our units to possible tasks/attacks
 	this.canBuildUnits = true;
 	if (!gameState.getOwnStructures().filter(API3.Filters.byClass("CivCentre")).hasEntities())