Say you’ve got an adventure that calls for a combat event: waves of trials are going to pour down on your PCs’ heads, and you want to keep the time pressure just the fun side of intolerable. But there’s a problem: you really aren’t positive at what speed your players will be able to cope. Unleash the hordes too fast, and they drown in monsters. Unleash them too slowly, though, and you’ll lose all your tension. It’d be even worse if you obviously revealed a new threat every time they defeated the last one: no hope of getting ahead with good tactics and, eventually, no pressure of finishing one wave off quickly.
This system aims to counter that to some extent. It leaves the flow of time within the event mutable, but still following a fixed system. The players may buy themselves some breathing room, but not too much, if they’re faster than you expect, but they’ll gradually build up some extra cushion if it turns out the combat spigot got turned up too high.
Step 1: The best possible scenario
Your first question is what you eyeball is the ideal case for your fight. Will the zombie outbreak take at best three rounds to clear out before the giant monster zombie breaks in? Should it take five rounds to put out the burning school before the dam starts to rumble?
List all of these times out on a rough schedule, for example:
Turn 1: Zombies attack
Turn 4: Giant zombie!
Turn 8: School on Fire
Turn 13: An ominous creaking
Turn 20: Undead Horror From the Briney Deeps!
Step 2: Threat Assessment
Now, break your threats up into their component parts. How many rounds do you estimate each piece of a threat will take? Set that information aside clearly so you can calculate it into your time dilation easily.
For example, three assumed rounds of zombies means that each 1/3 of the horde is a round. Four rounds of giant zombie means that each 1/4 of his HP is a round. Five rounds of the school on fire means each 1/5 of the successes to deal with it are a round. And so on.
Step 3: Make a Chart
Make a chart with each turn mapped out and space to list individual rounds under it.
In the example above, the chart would have at least 20 turns mapped out, with the significant ones noted.
Step 4: Bend Time!
Give each turn a number of rounds equal to the remaining rounds of threat. If the group reduces the threat as they go, reduce the number of rounds (or cut to the next turn). Whenever a significant event happens, add the rounds of threat for that event to the running total of rounds/turn. Have at least one round per turn, even if they clear the current threat. Go until it’s over.
Turn 1 is a 3 Round horde. It has 3 rounds.
- On 1.1, the players take some hits.
- On 1.2, the players manage to clear 1/3 of the zombies; since that was a threat marker, the rounds of threat is now 2 (so round 3 of this turn is skipped)
- On 2.1, the players make no major progress.
- On 2.2, another 1/3 are defeated, reducing the rounds to 1.
- On 3.1, the players still haven’t finished the zombies.
It’s now time for turn 4 and the Giant Zombie. The players still have around 1/3 of the original zombies left, so our new threat is 5 rounds.
- On 4.1, the players split their focus on zombies and the giant.
- On 4.2, they players finally finish off the horde (reducing the rounds to 4)
- On 4.3, they deal a major hit to the giant, dropping it below 75% (now there are only 3 rounds)
- On 5.1, they deal another major hit to the giant, dropping it below 50% (now there are 2)
- On 5.2, no big change.
- On 6.1, a surprising focus fire happens and the giant zombie drops. The threat is now 0.
- On 7.1, the players have a round to catch their breath before the next big problem…