So as I understand it some forts would use heated shot that would do extra damage and aid in starting fires on board the ships that would be attacking.

So this would apply only to fort batteries, not ships. I think either have something like +1 damage per chit like WoG has, or something like every 3 or 4 damage (# of chits) starts a fire, unless one of the chits drawn has the fire symbol, only one fire is started. Or the possibility of it starting multiple fires?

What do you guys think, does it sound too overpowered?