Battles only take place in Provinces where at least 2 players who are not Allied with each other have Force. The Battle involves all players who have any Force in that Province, even if they are Allied with each other. When a Battle takes place, the players involved will have a chance to use their Coins to try to gain certain War Advantages. These may not only end up changing the total Force each player has in the Province (and thus shifting the Battle outcome), but may also grant other benefits to the players.
Before a Battle begins, all players must clearly display their Coins and Ronin tokens next to their Clan Screens. A player must truthfully answer how many Coins and Ronin tokens they have, if asked.
NOTE: The Start of a Battle is right before players prepare to allocate their Coins for its War Advantages.
The Battle then begins! The involved players take all their Coins behind their Clan Screen and proceed to allocate them to the different War Advantage spots on the War tile. This is done simultaneously and in secret. Players may allocate any number of Coins to each spot (including zero), according to which Advantages they are trying to win. Any Coins the player doesn’t wish to allocate to a War Advantage spot are placed behind the Screen, but below the War tile (make sure your opponents can’t tell which spots you’re placing Coins on, and whether you’re placing any outside the War tile).
Once all players declare that they are done allocating their Coins, they all lift their Clan Screens simultaneously, revealing their bids.
Any Coins placed outside the War tile don’t count for this Battle and are returned to that player’s reserve. Players then proceed to compare the number of Coins allocated by each player in each of the War Advantage slots, starting from the leftmost War Advantage (Seppuku) and then proceeding to the right. Each War Advantage is won by the player who bid the most Coins on it. As always, if there’s a tie, the tied player with the highest Honor is considered to have the most Coins in that War Advantage. If no players bid any Coins on a War Advantage, it is simply skipped and the next one is resolved.
Only the player who wins a War Advantage is allowed to execute it. However, the player may choose not to execute a War Advantage they won, in case they only wanted to win it in order to deprive another player of it.
War Advantages are resolved one by one, from left to right. Keep in mind that the resolution of one of the War Advantages may affect the outcome of the resolution of a following War Advantage.
NOTE: Part of a Battle - Once a Battle starts, all players in it remain involved until the end, even if all their figures are removed by a “Start of Battle” effect, Seppuku, Hostage, etc. So they bid for War Advantages, may take hostages and even end up winning the Battle.