The reason why I'm talking about domination is that, when people are defending Mine Fields, their first response is that this building helps slow down warmongers. I do understand that there's a whole spectrum of play but many of the posts responding to me are addressing warmonger and domination style games. If you have any other styles you want to discuss, I'd be happy to talk about them. As for your example with Ethiopia, we all know that the AI navy currently cannot compare with their army. Therefore, the AI performs sub-optimal when it comes to naval invasions compared to the human player. Here, you stated that you have zero navy and have just ranged units. Does that include air units or just ranged land units? If you have air units, how much of an impact do they have on the war? If you have no air units, then why should anyone with solely an army be able to hold off a navy with the help of a single building? If the latter, I feel there's a bigger balance issue because decent players can hold off naval attacks without Mine Fields. You add in Mine Fields and the odds of winning decisively is that much higher. For me, I can see the human player absolutely abuse Mine Fields while the AI doesn't have a clue. Maybe I wasn't being clear with my thoughts. I'm speaking of warmongering dominating the world in the previous eras because that's where most of the UU are unlocked. If you are a warmonger, you will doubt be using that timing when UU becomes available to take advantage of the military spike. In addition to that, the Frigate and Cruisers are both quite strong for their time so those are also a good time to war. You are right that there can be formidable opponents into the late late game but a lot of games are usually decided by then, especially with runaway civs on other continents. I can see your reasoning but my question is why Mine Fields? Why are we using a building to achieve this? Why do we give so much defensive power to a single building that, in the hands of a human player, can be used to devastating effect while the AI don't know how to use properly? In addition, are air units not a counter to Battleships? Bombers have 6 range that they can attack. For a Battleship to attack and take no damage from the Bomber, it would require 11 Movements. I don't even know if that's possible as I can only see 10 being feasible and this requires some pretty big investments and the right civs. For me personally, Mine Fields doesn't help with balance as it gives human players one way to exploit to replace the other easily exploitable mechanic. Instead of us easily taking coastal cities, we now have a tool that let's us completely neglect a navy and maybe even an air force and still keep our coastal cities safe. The real question is whether or not we want to favor defensive or offensive play in the late game as asked by @Stalker0 . Until we can answer that question, this discussion will go nowhere. After all, defensive focused will promote Minefields and offensive focused wants it gone. I personally think we need a better look at the late game naval units regarding their roles and their counters. Since we're going for gold, I guess that won't be quite possible for the moment. Maybe I'll start a new thread since we aren't getting anywhere and I'm still not convinced a Mine Field is necessary for balance reasons. No, I'm saying that, until we enter Atomic Era, we only have two naval unit lines, one that's melee and one that's ranged. If you look at land units, they have upgrades throughout the ages so a Horsemen can eventually become a Tank. A Skirmisher can eventually be a Light Tank. Archers can eventually become a Machine Gun. Well, you get the idea. For navy, we have this awkward situation where Carriers and Submarines have nothing upgrading into them. To get them, you must build them from complete scratch with at most four promotions. With limited supply, it seems silly, to me at least, to expect diversity this late in the game when so many resources and time are invested in the eventual Destroyer and Battleship. This was addressing arguments that state we need diversity where you need air and navy to take down cities and how Mine Field helps force that diversity. Buffs can be a nice idea. Maybe instead of forcing the enemy to lose more movements, friendly units can get more defensive bonuses and extra movements. This kinda simulate your navy actively planting more mines and take advantage of the situation rather than having no navy and mines magically respawn to hinder further progress despite having no naval presence whatsoever.