Stunts Players Describe
Every player I’ve ever met would rather have their character do a cool stunt than a standard ‘vanilla’ attack move. “I pick up the table and drag it like a shield as I dart across the room, holding my pistol over the top and getting off as many shots as I can!”
A stunt like that is easy to picture. But how do you handle it in game terms? It includes factors of movement, encumbrance, cover, and multiple-shot accuracy, not to mention navigating obstructions in the room. Unless you’re using a game system that has overwhelmingly simple mechanics for all those things, you’ll probably have to slow the action way down and spend a couple minutes calculating exactly what attack bonus the player should get. Or, if you want to keep it quick and easy, you might say, “uh, ok, roll your standard shooting attack,” but that feels lame too, since it pretty much takes a cool idea and says, ‘no, we’re just gonna roll the same dice as always.’
Turning "Stunts Players Describe" (or SPD’s) into dice rolls is difficult. I think the reason is that we evaluate them in terms of common sense – how fast you can move while dragging a table, how much protection does the table afford, how accurate is your gunfire while crouch-running, etc. – and give bonuses and penalties according to how well we think this stunt would work in real life. ... And unless you’re a close-combat expert, that’s going to be a tough call. You’ll have to spend a couple moments mulling it over. The game will slow down. And if you use your “common sense” viewpoint and say that the stunt would only give you a +1, then you become Mr. Realism here to take the fun down a notch. ... I mean, because we all know that stunt’s coolness alone was worth more than a +1.
Instead, try evaluating SPD’s in terms of cinematic appeal. Movie characters often do stunts that aren’t realistic. Why? Because it looks cool! Your player is probably here to experience movie-like action anyway – so give him a bonus according to how cool and epic his stunt looks. For the shooting-crouch-running-table-drag stunt, I’d give a +2 or 3, depending how awesomely the player timed and/or described that mess.
What effect should a SPD have? Well, that depends what you’d expect this stunt to do in a movie. In this case, the stunt moves a character from one point to another without getting shot (with both his gunfire and the actual table serving to cover his movement), and if it’s really successful, it throws out enough lead to suppress the bad guys for another moment or two. So that’s your success scale. Failure means the character gets stuck partway and is now in a worse position than before. Success means he gets where he was going. A high success means he gets where he’s going and puts the enemy at some kind of tactical disadvantage.
Lastly, what ability should the player roll? With this approach to SPD’s, there’s no reason the roll for the table-shield SPD has to be a Shooting roll at all. Sure, there’s shooting involved, but there’s also speed, strength, agility, tactics, and even alertness. You could let the player roll any of these abilities. This means players can use the abilities they may never otherwise use, and it means sometimes they’ll use SPD’s to compensate for their character’s weaker skills. Using a different ability may change the effect that the stunt has (if the player uses Agility instead of Shooting, you might rule that a high success means he crossed the distance really fast, rather than suppressing the enemy), but this way your player never needs to be stymied for having the “wrong” abilities on his character sheet.
Your players don't want to have to know close combat tactics in order to do cool stuff in your game. They just want to play someone who knows that stuff. That means the players want a game where their ideas about stunts are also ideas that work. If a stunt would make your game feel more like a movie, let reward the player by letting him do it – and calculate bonuses according to its coolness, not according to game mechanics it doesn’t fit into.