We were playing Widow’s walk last night and happened to start haunt 59 which is the Fleshchild one. Since we had no monster, but one of us became a traitor, he kept his omen/item cards and started hunting us. We had a case where in a combat, the traitor attacked one of the players and after both rolled, they attempted to use the bloodstone card. Nowhere in the rules is explained, can they be used after both players in the combat rolled their dices? When is the combat declared finished? Its just stated “once per turn”, but can such cards be used after the opponent attempted a roll or it should be after the card holder roll?
The Bloodstone Omen Card says:
Once per turn, you may lose 1 from any trait to add 2 dice (maximum of 8 dice) to your trait roll.
An Attack (or Defense) roll is not considered a Trait Roll. The traitor would not be able to use this card to buff their attack. Trait Rolls are explained in more detail on page 13 of the 2nd Edition Rulebook.
Trait Rolls: Sometimes a card, room tile, or haunt tells you to attempt a roll based on one of the explorer's traits (Might, Speed, Knowledge, or Sanity). When that happens, roll dice equal to the number your explorer currently has in that trait... An attack roll isn't a trait roll, even though it involves Might or some other trait.
A Trait Roll would be if a room card tells you to make a Might/Speed/Sanity/Knowledge roll, the haunt tells you to make a sanity roll to do XYZ (besides attacking), or if a room tile has some sort of trait specific text (such as the Collapsed Room tile where it asks you to make a Speed Roll).
In short, if you are attacking another player, or defending against an attack of some kind where another player is rolling dice against you, this is not considered a Trait Roll.