- Double the amount of dice the player rolls to see what they get?
- Roll damage normally, then double the amount?
- Roll damage normally, then add that to a maximum damage result?
- Something else entirely
The first two are the most common ones I've seen. You either double the amount of dice rolled for damage, or double the result of a damae roll. However, I'm kind of fond of the third option. I picked it up from a GM at GenCon and have used it in games I run where that kind of mechanic exists. It gives the players a lot more bang out of their criticals, ensuring they get to do at least one instance of their attack's maximum damage. It also makes enemy crits hit harder by doing the same in return. In general, it just makes crits work a lot better and feel more worthy of the celebration you get from it.
No one likes the anti-climax of rolling a crit only to get snake eyes on the dice and doing 4 damage with a critical hit from a two handed sword. So, I figure, why not let the crit hurt? It just hurts both ways.
How about you?