WMD

[Outlaw Josey Wales]

What RickyB said. If everyone agrees to a house rule of no WMD, there will be strong stacks along the front. If WMD is a possible option, units would be more spread out to avoid destruction. It does make a mess with blocking hexes, especially an intersection with many roads. I believe it stays for the duration of the game. It has been years since I have seen that in a game and only the one game.