How do you handle car chases in your games? Chases are a staple of action films, but rarely get good treatment (if not ignored altogether) by RPGs that usually focus on hand-to-hand duels or gunfights.

I'm mulling car chase rules. I imagine the same basic system should be able to handle aircraft, swimming, foot and horseback chases, but car chases are the main event in the action films I know and so probably the best to focus on.

I reason that the two metrics in a car chase are (a) range and (b) maneuver room, measured across arbitrary change-phases.

A. Range is measured in range bands, from 0 (pacing) to 4 (lost them). Skill, terrain, car handling, conditions and horsepower factor in adjustments. Each phase has a chance at increasing, decreasing or status quo the range bands.

B. Maneuver room is measured in feet, equaling the road width minus the car width, halved. E.g., a 6' wide car on a 24' wide road has a maneuver room of 9. MR is like the "hit points" of your car: if you reach negative MR you crash. It is altered through maneuvering around other cars, curves and obstacles.

Prep: Ideally, the GM plots out a chase map beforehand, marking curves, splits and termini. Then he notes road width, obstacles like dumpsters and traffic, and conditions like black ice, rain or mud. Divide the chase map into phase-lengths and then the chase is ready to begin.

Play:
1. At the start of each phase, the evader and pursuer each secretly select a Magnitude (1, 3 or 5), then reveal their choices simultaneously and compare them on the Chase Matrix. The results give the respective effects on maneuver room and modifiers to range band rolls.

2. Evader and pursuer (presuming they haven't already crashed at MR -1), make any necessary driving rolls vs. curves and obstacles, modified by conditions.

3. Resolve crash effects.



"Contested skill roll to change range band by 1" Both cars roll skill; if they both succeed or fail, range band is unaltered, otherwise range band changes by 1 however the winner chooses.

"Skill roll to separate" The Evader may try to separate from the chase, veering off into an alley, branch or off-road. Pursuer may roll to follow.

OPTIONAL
Rams: When at range band 0 or 1, a car may roll contested skill to attempt to ram its opponent. Success costs the rammed car MR = 1d6 X (difference in size + difference in skill). Failure costs the rammer 1d6 MR X (difference in size + difference in skill).

Size = 1 (motorcycle), 2 (car) or 3 (semi)
Skill = 1 (new driver), 2 (seasoned) or 3 (pro)

For me, the best chase mechanics I've used were from the old James Bond RPG. It was always a highlight because of how the system combined tactical depth with the high-stakes tension you expect in action scenes.

What made it work was its bidding mechanic, where both sides would decide how much risk they were willing to take each round. The higher the risk, the greater the potential payoff, but the higher the cost of failure too. The party that bid the most would act first. It added even more tension because players had to think carefully about how much they could afford to risk at any moment.

Players could choose from a variety of maneuvers like hard turns, driving through obstacles, etc., each with specific penalties for failure. Every choice felt important because each had real consequences if you didn't pull it off. We'd end up running chases in almost every game because they were such a blast.

You could maybe adapt a similar bidding mechanic to what you're working on, perhaps in place of, or alongside, your Magnitude choices. If the players can decide how much they want to risk in a given phase, you could see even more dramatic changes in range or maneuver room as they push their luck.

By the way, for anyone curious, these mechanics also exist in Classified (the "anonymous" modern version of the James Bond RPG), though I haven't personally tested that version.

I've always liked the Wushsu for its dice pool mechanic that is driven by details.  The more cool details and action you describe, the more dice you get for your pool.  It brings out cinematic action for martial arts, car chases, aircraft dogfights, parkour action, and more.  Channel your inner director or stunt coordinator. 

You can easily plug that that concept into any system.  Running d20?  Come up with five or six details/stunts and roll five or six dice and see how many successes you get and add that to your lead.

https://www.drivethrurpg.com/en/product/143146/wushu-black-belt-edition (pwyw)

Thanks for the ideas. Risk bidding, and imaginative details.

If one is shooting for cinematics, reasonably realistic ones, why not analyze actual film car chases and see how they can be replicated systemically. Just as most games' combat systems don't really simulate either reality or films, but a kind of action u-topia, it can be a trap to devise car chase rules that have no mooring in film or real life.

To this end, I'm going to rewatch the chase scenes from The Terminator and see how to rule those scenarios... If I can get some rules to capture that, I can extend it and analyze other film chases and see if I can wrestle out a useful general system.

Quote from: SuperJefferson on October 11, 2024, 03:52:46 PMFor me, the best chase mechanics I've used were from the old James Bond RPG. It was always a highlight because of how the system combined tactical depth with the high-stakes tension you expect in action scenes.

What made it work was its bidding mechanic, where both sides would decide how much risk they were willing to take each round. The higher the risk, the greater the potential payoff, but the higher the cost of failure too. The party that bid the most would act first. It added even more tension because players had to think carefully about how much they could afford to risk at any moment.

Players could choose from a variety of maneuvers like hard turns, driving through obstacles, etc., each with specific penalties for failure. Every choice felt important because each had real consequences if you didn't pull it off. We'd end up running chases in almost every game because they were such a blast.

You could maybe adapt a similar bidding mechanic to what you're working on, perhaps in place of, or alongside, your Magnitude choices. If the players can decide how much they want to risk in a given phase, you could see even more dramatic changes in range or maneuver room as they push their luck.

By the way, for anyone curious, these mechanics also exist in Classified (the "anonymous" modern version of the James Bond RPG), though I haven't personally tested that version.

yes! i was also thinking of mentioning james bond, i feel that's the best option when it comes to those type of high octane scenes, as it's an interesting system that's still very lightweight

Living in America, we do all car chases as LARP.