Pillaging a citadel destroys it and it's tile and all adjacent tiles owned by the citadel owner (2-tile radius if the land owner has Lebensraum) become neutral territory, so that both sides could grab the land again (via a new citadel or natural land expansion or tile buying). The only reason the tiles switched side is because of the military presence, so it makes sense once you remove it the tiles flip. Now let's compare before and after the change. Before: Citadel is mostly cheap land grabbing tool. AI likes to spam it left and right, even to hurt the player by taking his non-resource tiles, where the AI doesn't gain anything There's no point to defend citadel all the time, it can be repaired if pillaged Because there's no penalty or extra costs other than GG mindless spamming of citadels is encouraged Peaceful player can't counter-citadel, as he has much less GG The only way to get your land back is to go on a conquest. Gets worse if citadeled from different sides Lebensraum is crazy broken, you can deprive a city of all its tiles without declaring war. After: Citadel is a strategic tool first, a military outpost that you have to, actually, defend (shock!) Losing a citadel would hurt More thoughtful placement of citadels is encouraged Both peaceful player and warmonger can counter citadeling. Warmonger still has advantage though, thanks to stronger army Lebensraum is balanced to some extent as potential damage of losing a citadel increases I think the current situation heavily favors warmongering, and the change would help peaceful players and bring balance to this aspect of the game. Initially I wanted to suggest the tiles return to the original owner after pillage but that would be too hard to implement so a simple solution as making tiles neutral would work.