View Full Version : Chase Mechanics

2012-10-16, 04:50 AM
Are you guys familiar with any roleplaying game that uses abstract rules for chases, movement and the like? Something without maps.

2012-10-16, 04:53 AM
Yes. Spririt of the Century have a pretty interesting rule on chase. I'm only familiar with that variant of FATE though, so I don't know if any other FATE variant use it.

Let me see if I can find it

Edit: Found it on the online SRD, but I don't know how to link just this part, so I'll just paste it here.

◉ Chases [Drive]

Despite the caveat about speed, Drive mostly comes up in one important context: chases! Sure, sometimes there will be rolls against specific difficulties to get out of a burning building in time or the like, but really, if a character has a substantial Drive skill, it’s so he can come away as the winner of a car chase.

So here’s the first rule of chases: they aren’t about speed. Sure, in a straightaway, the faster vehicle wins, no question, but that should almost never happen. Car (or any other kind of vehicle) chases end when one party is no longer in the chase, usually because they’ve crashed violently (and possibly explosively).

Car chases play out like any other conflict, with one or two small differences. Vehicles have their own stress track (see Gadgets & Gizmos, page XX), but they do not “attack” each other as is normally the case in a conflict. Instead, they engage in a steadily escalating series of dangerous actions, until the lesser driver is weeded out.

At each exchange in a chase, the driver of the lead (“chased”) vehicle calls out an action. Even if other things are happening at the same time as the chase, this action declaration is made first, regardless of initiative. The driver declares a difficulty of his choice, and describes what complicated and dangerous maneuver he’s performing that this difficulty matches. He then makes a Drive roll against that difficulty.

If he succeeds, he pulls it off, but if he fails, it goes less well than planned – the car gets banged up some or slips out of control, and the car takes stress equal to the number of shifts the character missed the difficulty by (as if an opponent had rolled the difficulty as an attack).


Next, the driver of the pursuing vehicle (see below if there’s more than one vehicle) rolls against the same difficulty. If successful, the car takes no stress and inflicts stress to the lead car according to the shifts on its roll as it manages to get close, slam bumpers, fire some shots, or otherwise make trouble.

Alternately, if the pursuer is not looking to damage the lead vehicle, he may roll for a maneuver. If he fails, his car takes stress as if the difficulty were an attack – poor driving or overzealousness has had him sideswipe a vegetable stand, or rip up his tires on a tight turn.

Eventually one party or the other will be taken out, and that should pretty well handle that – if the chased vehicle’s still in motion, an escape; if a pursuing vehicle’s in play, capture!
◉ Multiple Vehicles [Drive]

Now, this is all well and good for when one car is chasing another, but chases are usually a lot more crazy than that – it’s a lucky hero who is only pursued by only one vehicle! Usually, if one car goes down, another one is in its place, and villains are famous for having guys with grenades on just the right rooftop as the hero tries to get away.

Multiple vehicle chases usually use the minion rules (see page XX), with each car equating to a minion, and all of the pursuers acting as a single unit making a single roll. If there’s a named pursuer with a handful of unnamed companions, the minion vehicles attach to the named leader normally.


However, if there are a lot of cars – say you have a named pursuer who has 10 minions – it’s a little hard (and anticlimactic) to have all of the vehicles on the field at once. When you look at movies and the like, the usual pattern is that a few cars show up in pursuit, they crash, and new cars come in to take their place, and this process repeats until there are no more reinforcements.

With that in mind, when you want to play out a more extended chase that has this kind of pacing, the Chase Scene rules become appropriate.
◉ Chase Scenes [Drive]

Chase scenes occur when the players are being pursued by a large enemy force. In a chase scene, the named pursuer stays out of the chase, at least initially. Over the course of the chase, the pursuing minions come at the player sequentially, with a new minion coming in as a prior one is taken out. This continues for the duration of the chase until the pursuer is out of minions, at which point, he enters the fray and the chase is then resolved normally.

Because the pursuer is not on the field, the minions never attach, so they use their own skill, which is often to the fleeing character’s benefit. In return for this, the pursuing villain is given a few tricks to balance the scales. (Players, being heroes, don’t use these rules, since they are potent individuals of action, rather than masterminds working through lackeys.)

At the beginning of a scene, the GM-controlled pursuer is given a certain number of points, which represent the total value of the pursuit. Five points makes for a very short chase, 10 for a one meant to be a major feature of this section of the story, and 20 can make for a chase scene that will take up a goodly portion of the session, as a climax to the action.

The baseline use of this value is to determine how many minions the pursuing character has. Each minion costs a number of points based on its value (1 for Average, 2 for Fair, 3 for Good). At the start of the chase, the pursuer can spend as many points as he wants (up to the total value of the pursuit) in order to buy minions. He can choose to have all of these minions go after the characters now, or he can hold some of them in reserve (in which case the reserve vehicles will enter the chase one by one, as individual minions are taken out). Also, at any time there are no pursuing vehicles (i .e ., all the minions that he’s bought have been taken out), he can spend points to add a single additional pursuing vehicle, which immediately enters the chase. More importantly, the pursuer may also spend 1 point per exchange for any of the following effects:

Allows the pursuing character to add multiple cars at once. By spending one point, he may spend additional points up to half his remaining total on purchasing additional cars, which are immediately added to the field. These vehicles must all be of the same quality as the car already in play and each other. Adding extra vehicles allows them to get the bonus for being in a group, but has the drawback that overflow damage will roll onto the next vehicle as it does for minions (this does not happen when there is only one pursuing vehicle).
Road Hazard
The pursuers have managed to get someone ahead of the lead car and may launch an attack against the lead car, using the villain’s Drive (or Pilot, when appropriate) skill as the attack value. Other pursuing vehicles do not need to defend against this attack, since in theory, at least, they’re aware that the hazard is forthcoming. This is one of main tools the villain may use to offset the loss of not involving himself directly.
One of the pursuing vehicles has someone with a gun in the passenger seat, and the addition of bullets into the mix makes things all the more dangerous. Any time the lead car takes stress, it’s increased by one as long as this guy is shooting. The guy with the gun can be removed when that car is taken out (reinforcements do not have a gun unless points are spent for it).
The Last Pursuer

If the pursuing villain is not going to join the fight himself, he can try to end the chase with one last, tougher-than-usual vehicle. This is the last ability the pursuer can use, and costs all his remaining points (minimum of 1). If the Last Pursuer is used, the villain himself cannot subsequently join the chase.

The last pursuer is always more impressive than the previous vehicles. Perhaps it’s big and armored, sleek and black, or maybe it’s something completely unexpected, like a biplane. It is always treated as a Good Minion, with one extra box of capacity for each point spent beyond the minimum.

It also has one other benefit from this list:

+3 Stress Boxes
+1 to Drive Rolls
Armed – Always treated as having the Shotgun! Effect.
1 point of armor (see Gadgets and Gizmos, page XX)
Alternate Movement – the pursuer can move in ways the lead vehicle can’t (such as flying, or water). Mechanically, this means that the pursuing car can opt to avoid almost any hazard, treating it as if the pursuer automatically succeeded at the roll, but inflicting no stress on the pursuer for doing so. The pursuer is only obliged to roll if the lead car can come up with a maneuver that forces the pursuer to respond.


Dramatic Entrance

This is the moment when the named pursuer reveals himself, and begins the end of the chase. If the GM has used “The Last Pursuer” already, this option is off the table. This costs all the the pursuer’s remaining points (minimum 1) and triggers a Road Hazard for the fleeing vehicle, as the pursuer appears in a colorful and hopefully hazardous way. The stats of the pursuer’s vehicle depend on the pursuer, and if he does not have a signature vehicle, he may use the same rules as The Last Pursuer, above, replacing the minion quality with his own skill.

Once the pursuer is out of points and there are no pursuing vehicles left, the fleeing vehicle finally escapes.

◉ Passengers [Drive]

Each exchange, one PC or named NPC passenger may assist the driver, provided he has the means to do so. This allows him to contribute to the chase, as long as he finds a way to describe it, be it shooting at the pursuers (Guns), pushing a crate out the back (Might), or just shouting “look out!” when dramatically appropriate (Alertness). The passenger rolls his skill while the driver rolls his Drive as usual, and the driver may use the higher of the two results. (The only limit on this is that the same passenger may not help two exchanges in a row .) Note that this is a single result, not two – for instance, a passenger who is shooting does not get normal attack results, just the ability to let the driver choose between two rolls. This said, by dint of being passengers in the same vehicle, all characters – even those not able to roll in that exchange – may offer to spend fate points out of their own pool on behalf of the driver, so long as they supply a bit of color dialogue, e.g., “Alleyway ahead!”

Furthermore, there’s nothing saying that characters along for the ride can’t be doing other things that don’t contribute directly to the chase. While they can only act against the pursuers by partnering with the driver as described above, there’s nothing to say that your car chase can’t feature the Academics guy in the back seat furiously trying to read through the book the heroes just stole from the villain’s lair… just in case the guy’s minions catch up with them and the book returns to its owner.

The reason for these rules are twofold. First, if all the passengers were engaging in full participation at the same time, the chase would finish very quickly and would almost certainly be less interesting. But second and perhaps more important, by focusing the chase experience around the person in the driver’s seat, the driver’s shtick of being good at driving gets backed up. Chases are uncommon enough that, when the opportunity to shine comes up, the driver should most certainly get the spotlight.

2012-10-16, 04:56 AM
Yes. Spririt of the Century have a pretty interesting rule on chase. I'm only familiar with that variant of FATE though, so I don't know if any other FATE variant use it.

Let me see if I can find it

I'm familiar with Spirit of the Century, but from what I understand chases in FATE work like, well, everything else in FATE. :smallbiggrin:

2012-10-16, 04:57 AM
Well, I posted it already anyway so yeah :smalltongue:

2012-10-16, 05:48 AM
If I recollect correctly the 3.5 system has one... I think it is in the Eberron Campaign Setting but I'm not entirely sure about that.

2012-10-16, 06:08 AM
If I recollect correctly the 3.5 system has one... I think it is in the Eberron Campaign Setting but I'm not entirely sure about that.

There're two, three if you count the PF one. One's in DMG2 though I don't recall if it's reliant on a map or not. The other is in stormwrack and is intended for ship-born chases at sea. PF's version uses chase cards; which, I think, are available for print on the PF SRD.

I don't remember a set of chase rules in an eberron book, but I could be mistaken, or simply not have that particular book.

2012-10-16, 06:09 AM
I really like the PF chase rules, but I was looking for something different. Maybe I'll just try mixing it up with FATE.

Well, I posted it already anyway so yeah :smalltongue:
Thanks, man. ^^ I guess what I'm looking for is more like an abstract positioning system.

2012-10-16, 06:55 AM
I designed an abstract chase mechanic, it was just a little tweak to a generic skill resolution system, so it's not very robust, but I believe it works.

You have a certain # of rounds, between 1-6, to either catch someone before they escape, or to escape from someone, and this is based on how far away you are initially (1 would be very far away, 6 would be right next to you). The terrain and/or obstacles determines the target number for your Athletics check, and the NPC's speed determines how many successes you need to get in that time (regardless of whether they are the pursuer or the pursued).

For example, Han Solo is trying to lose a bunch of TIE Fighters in an asteroid field. He starts with a pretty decent gap between them, so he has 4 rounds for this pursuit. The TIE Fighters are the NPCs, and their speed category indicates that Han needs to get 7 successes in those 4 rounds to escape. Since this is an asteroid field, the Difficulty is pretty high.

You could make a preliminary roll to get some advantage points that you could spend to give yourself different benefits, and there are rules for critical fumbles, but that's the primary chassis there.

That's extremely simplistic, and some might even say un-engaging, but it uses the same framework as all other skill challenges in my homebrew system, so I was going for familiarity and functionality over depth or unique-ness.

2012-10-16, 10:15 PM
Dresden Files RPG is FATE-based, so I dunno if their chase system is like the other FATE games or not. I imagine it is, but it's the only one I've ever read, so.

2012-10-17, 09:14 AM
If you're running d20, Spycraft actually has a surprisingly good set of chase rules. Shadowrun also has a decent enough system.

2012-10-17, 09:53 AM
Burning Wheel Gold has this: its "Range & Cover" is an abstract chase/skirmishing subsystem. I'm still wrapping my head around it, but there's some cool ideas there.

I'm also working on one for a zombie game, and it basically works like this: a fugitive builds up an "Escaping..." quality (stealing from Fallen London/Echo Bazaar here), and each round, they roll a d20, trying to beat their Escaping... quality. If they fail, they get caught. However, if they build their Escaping... up to a certain point, they automatically get out.

2012-10-17, 08:05 PM
I just use D&D d20 rules. Speed is most important, followed by Constitution (to keep running), but also Balance, Climb, Jump, and Tumble for moving around obstacles.

2012-10-17, 08:35 PM
I really like the PF chase rules, but I was looking for something different. Maybe I'll just try mixing it up with FATE.

Thanks, man. ^^ I guess what I'm looking for is more like an abstract positioning system.

Well, there goes my suggestion for PF then.

2012-10-17, 08:39 PM
The skill challenge mechanic of 4e is a good basic idea, IMO, but as most people know the rules are pretty borked if used as-is.