Gamer Without a Cause
I immediately thought that this should be a rule and was disappointed when it was not. In the 2 games I played. those first 3 heroes did a majority of the work and 1 hero never got on board to play (sad) and the other hero showed up on the last turn and just ran towards the action. I want it to feel like a 5 hero game and not a 3 hero game.
The house rule I would try the next time I play.
1. Hero that is 2 or more zones from an enemy may use all 3 actions and remaining gold to go back into reserve.
2. all wounds on hero would remain with them and be present if/when they return to active status.
the 2 zones would keep heroes from getting close to death and then popping out to safety.
I also think when a hero is knocked overboard they should have an option to "tag out" and let another hero take their place in the following turn. . .
There are only 3 heroes allowed on the deck of the ship, so think of it that way.
If one gets knocked off and one 'tags in' his place, then the other just sits in the water, since he can never get back on the deck of the ship.
Being able to come up and spend all your gold on an attack and then go back in reserve would simulate someone coming out, throwing a grenade and then running back below deck.
Sure it sounds like Variant stuff to me, but the game is pretty balanced around 3 heroes. Using 5 makes your turns longer, kills stuff faster and really empties out the board.
It's just meant to be played with 3.