A Walk in the Dark A look in to the mind of an RPG designer

Hazard: Fleeing Rats

DISCLAIMER: I'm going to be talking about a movie that's over 20 years old. Don't start screaming about spoilers.

A while back, while I was in one of my design sessions, I found myself watching Indiana Jones and the Last Crusade for the umpteenth time (why? Because it was on TV! Duh!). On or about the same time I was trying to think of something to put in a tomb, the scene under the church started. You know, the one where Indy and Elsa (to avoid calling her "the hot chick", I actually had to look her name up) are plodding through a sewer filled with rats.

When they reach the resting place of the knight, the creepy guy from the Brotherhood that's following him lights a match and drops it in to the river of oil. The next scene shows what can only be described as a wave of squealing rats trying to escape the oncoming flames.

Suddenly it struck me: if you're happily walking through a narrow corridor when a horde of a million tiny rats begins to barrel towards you, what would you do?

I know there is a "Rat Swarm" monster, but that's not quite the same thing. The rat swarm in the Monster Manual is an actual monster and is handled as such: it occupies a specific square, attacks a single target, takes damage until it dies, etc... It arguably has intelligence. That's not what I'm thinking. I'm thinking of the "yelling 'fire' in a crowded theater" sort of mindless panic where tiny, otherwise harmless rats freak out and run in unison without thinking of anything besides "FIRE BAD!". A sea of endless rats small enough that they easily pass through the player's space but individually not big enough to be attacked directly.

And standing anywhere in their path is probably not a good idea.

And thus the "Fleeing Rats" hazard was born...

Now the wave isn't "endless" in the literal sense (although, with magic, anything's possible) so it has a certain size: it has fixed dimensions - a 2x10 grid of contiguous squares - that moves like a snake, in a straight line away from something bad towards something... less bad.

Think of the possibilities this allows:

• The party's pyromaniac can take great pleasure in immolating several thousand rats. You, as DM, can then figure out how to amend the hazard to handle what a swarm of rats on fire would be like...
• The party should be able to see the rats before they arrive, but if you're a particularly evil DM you can treat the swarm's arrival like a surprise round.
• This could be a perfect lead in for something that the players should be afraid of: whatever spooked the rats in the first place.
• Deep down inside, every adventurer wants to be Indiana Jones. They're just afraid to admit it in mixed company.

I'll also point out that this trap will not only work outdoors as well, but it doesn't have to be rats. Spiders, ants, squirrels... Pretty much any small creature that runs on all fours and isn't too bright will work.

So how would you change this?

ADDENDUM: I know I warned you about spoilers, but I don't think I actually included one.

So here ya go... Ready?

...

Indy's father is Keyser Soze.