"The Boom Mine stops the enemy in their tracks! Its armor piercing blast does double damage to tanks."
Summary
Boom Mines have the same function as normal Mines, but they deal much more damage, and double to tanks.
Boom Mines deal splash damage within a very small range.
Offensive Strategy
Do not let your Troops (especially your most valuable ones) step on a Boom Mine, as they are very deadly! However, if your Troops have at least 1 tile spacing, the Boom Mine will only destroy 1 of them.
An Artillery or Barrage can be used to trigger Boom Mines before deploying troops.
Defensive Strategy
Place Boom Mines away from normal Mines and other Boom Mines, as they are capable of dealing with a group of troops alone.
Having some distance between Boom Mines can also prevent attackers from triggering all of them through a Barrage.