Racing the Clock is one of the staples of suspense. The hero doesn't just have to accomplish some task, they have to accomplish the task before something else happens. Even if it is just a simple situation of a hostage dying when the sand runs out of the hour glass it can add tension because more than just the result of an action hinges on whatever is happening.
Race the Clock scenarios are common in all sorts of games, but I've always felt they were a bit clunky in table top RPGs. Time is just too malleable and too disjointed. 30 seconds can take 5 hours of game to resolve, and 3 years can go by in a heart beat. So how do you do it? Today I want to talk about that.
Step 1: If You Want Tension, Use Trackable Units
One of the classic uses of racing the clock is having to get somewhere, or beat someone, before sunrise. The problem is sunrise is seconds/minutes/hours away, and that isn't what your game is tracking time in. Because of this, if you want people to feel tension from racing the clock, you need to use trackable units. And you need to use the same units throughout the whole situation.
"The sun will rise in 3 hours" is what your brain will want to say, and then a fight will break out and suddenly you're tracking things in rounds and how long are rounds in this game? Was that fight 5 minutes or 30 seconds? What if rounds can have different times like in Edge of the Empire?
Better to keep it simple. "The sun will rise in 40 rounds." It sounds a bit arbitrary, but it is a unit you can keep track of. You can resolve actions in rounds. "You can bust the door down, but it's going to take 7 rounds, 5 if you can beat a 23 on the athletics check. Or you can try to pick the lock which will only take 3 rounds but has a difficulty of 25 on the lock" and it meshes with combat perfectly. You can take rounds off the timer if the players spend too long arguing, or add them back for particularly clever ideas. Yes, you can do that with other measurements, but when everything is using the same unit it feels more real and trackable and that is what you want.
Step 2: Keep The Timer Visible
Make the timer visible. If you have a digital display, great. If you are using dice, great. Just make sure that the timer is visible to all the players, and make sure they see you as you count it down. Announce when you hit milestone numbers. If you give them 40 rounds to do something, let them know at 30 rounds, 20 rounds, 15 rounds, 10 rounds, 5 rounds, 4 rounds, 3, 2, 1...0.
Having the timer visible means you can also express time used/wasted/gained without having to say a thing. People are arguing in circles about bashing a door down or picking it, drop the timer. Someone remembers they can make sunrise happen later than it should somehow? Add to the timer.
Just be warned that some groups will just argue more if they see the timer going down while they argue. You then have to choose between docking more time (fairly) or pausing to settle the debate. Heated discussion IC is good. OOC threats and name calling not so much.
Step 3: Watch the Quiet Players
During situations like this it can be easy to lose track of quiet players, and with time being of the essence that can make said quiet player feel cheated. So be sure to watch them. Especially when they act. More often than not I've had a quiet player casually, and unnoticed by the rest of the players, just bypass a puzzle or challenge and move on only to have everyone wonder how they did it later. Of course, they can take time to figure out what happened, but..well, it takes time.
Step 4: Set Your Goal Appropriately
This should maybe be higher, but I don't think it is as important as the other three. Be sure to give enough time to accomplish the task, even if things don't go perfectly. If the timer requires a perfect run to be done expect to have the failure condition come up and for players to feel cheated. If you think your players are going to make it to the big fight with 15 rounds to spare, make sure they can actually win that fight in 15 rounds and not by just rolling perfect criticals every round.
Setting a timer appropriately is going to be one of the harder things. Too much time and you lose tension. Too little time, and what is the point? Get it right though, and things can play out very nicely. Just remember, the idea is to add tension while having fun, not to add tension at the cost of fun.