A d20 car crash

I've got a game set in 2006 where I need to have a car crash.

I was thinking of just doing "falling damage" (1d6) for every 10 m.p.h. (Maybe a saving throw for half, but which one--Reflex or Fortitude?)

I am not looking for any detailed car crash system; I will not be buying any books or .pdfs just for this one in-game incident.

TIA for any thoughts.

Are you using d20 Modern? There are decent crash rules in there, and those rules are free from the SRD. It doesn't seem like much damage, but a head-on crash at most normal speeds is going to put a major hurt on any ordinary car -- as it should.

I had a great d20 Modern session that consisted almost entirely of the party heading into town to find out more information -- and then one PC jaywalked, got hit by a car along with another PC who tried to push him out of the way, and the car skidded into the oncoming lane and hit another car, with both cars doing 35 or so.

The next few rounds involved breaking open doors that were jammed shut in order to drag out the unconscious car occupants, stabilizing them, and dragging them away from the burning vehicles before they exploded -- and the party KNEW that the cars were going to explode. They just didn't know when. Fun session.

An Acura doing 35 hits the average d20 Modern damage threshold pretty quick.

Excellent story, Tacky!

This is a single car, in the process of slowing down, which got hit by a bullet (tire blown out) and then crashed into a row of parked cars which served as a barricade.

I will look at the d20 Modern crash rules. Thanks for the tip!

And stay tuned for the upcoming Chase rules from Adamant Entertainment's Masterkit series. Those are in final tune-up right now and hopefully will be ready before long. They build off the vehicle rules in d20 Modern, make use of ideas from both Spycraft and Grim Tales, and they rock hard.

I know. I wrote them.

The idea is to let you do chase scenes like you do combats -- exciting, fun for all the players, without a lot of pointless clutter to slow you down.

Here are the relevant d20 Modern collision rules.

Pick the fastest speed among the objects:
Alley speed (1-4 mph) d2
Street speed (5-34 mph) d4
Highway speed (35-80 mph) d8
All out (81+ mph) d12

Pick the smallest object size in the collision:
Collosal: 20 dice
Gargantuan: 16 dice
Huge: 12 dice
Large: 8 dice
Medium: 4 dice
Small: 2 dice
Tiny: 1 die
smaller than tiny: 0 dice

Apply the appropriate multiplier:
collision with stationary object: x1
collision with moving object, head-on or 45 degrees from head-on: x2
collision with moving object, perpendicular: x1
collision with moving object, from behind or 45 degrees from behind: x1/2
side-swipe: x1/4

This is the damage to the vehicle (and to whatever it hit). Occupants receive damage as follows:
vehicle provides no cover (e.g., a motorcycle): x1
vehicle provides 1/4 cover (e.g., a helicopter with cargo doors open): x1/2
vehicle provides 1/2 cover (e.g., rear bed of a pickup truck): x1/4
vehicle provides 3/4 cover or more (e.g., a typical car or truck cab): x0
occupants may make a reflex save (DC 15) for half damage

You read that correctly. Under d20 modern rules, occupants of a typical car NEVER take damage from collisions (unless the driver loses control and the vehicle rolls over or the vehicle takes enough damage to explode).

Speeds of both objects are reduced by two categories.

The driver has to make a Drive check (DC 15) to avoid losing control of the vehicle.

If the collision disables the vehicle (reduces it to 0 HP or less) AND deals damage greater than or equal to half of its full normal hit points (Most cars have HP in the 30s and hardness of 5), the car explodes in 1d6 rounds, dealing 10d6 damage to everyone within the vehicle (Reflex save (DC 20) for half), and half that much to everyone within 30 feet (Reflex save (DC 15) for half). A vehicle reduced to the negative of it's full HP total (e.g., -36, for a car with max HP of 36) is destroyed and cannot be repaired.

Thanks, babomb! You da bomb! (we need a "groaning smiley" for puns and overused jokes )

That's what I'm going with. Rolled 21 points of damage on 8d4 (20 m.p.h. large car hitting another large car). Now for some saving throws for the occupants.


(and thanks for moving the thread, mods; sorry about that!)

babomb said:

You read that correctly. Under d20 modern rules, occupants of a typical car NEVER take damage from collisions (unless the driver loses control and the vehicle rolls over or the vehicle takes enough damage to explode).

Click to expand...

Yeah, that's odd. I want this crash to kill people though (they're the bad guys), so some of them are dyin' from the crash.

babomb said:

vehicle provides no cover (e.g., a motorcycle): x1
vehicle provides 1/4 cover (e.g., a helicopter with cargo doors open): x1/2
vehicle provides 1/2 cover (e.g., rear bed of a pickup truck): x1/4
vehicle provides 3/4 cover or more (e.g., a typical car or truck cab): x0
occupants may make a reflex save (DC 15) for half damage

Click to expand...

I, personally, would up all of those by x1. So no cover would be x2 and 3/4 cover would be x1. Keep the reflex save for half. I've seen more than my share of bike accidents, and most of the time the bike comes out looking better than the rider... Just how I'd do it.