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



On The Road (Part 2)

This is a continuation of yesterday's post in which I babble on about implementing vehicles in 13th Age.

Maneuverability and Skill, Revisited

In the three examples I provided - the motorcycle, the car and the 18-wheeler - the maneuverability and skill levels were equal, which seem to imply that there really isn't a need to define them both. So I sat down to try and decide what would represent the two extremes.

High Maneuverability, Low Skill: The Bicycle

Although I personally cannot ride a bicycle safely (due to an inner ear condition), it doesn't take a whole lot of experience to ride a bike. Heck, my son was doing it at an exceedingly early age. But someone who's very good at riding a bike can do some rather amazing things with it, if the X Games are an indicator.

Low Maneuverability, High Skill: The Forklift

Now this may sound odd, but I actually know how to drive a forklift. You would think it's easy but it actually isn't simply because it's counter-intuitive and not what you're use to because they usually steer from the back. So you pretty much drifting everywhere, and it takes some effort to get a feel for it before you go and slam into some freight.

Now think of two examples for a second... They somehow exist in your game, and the PC elects to use them somehow... Are you seriously going to do a skill check if they can? Quite frankly, if a PC wants to launch himself in to the air and do some tailwhips while he's at it are you seriously going to roll a die to see if he fails doing something that awesome? And failing to drive a forklift would probably be the single most non-heroic thing you can have a PC do ever. If anything, I'd make the drive a little entertaining and have the PC slam into a pallet or two, but I'd probably never touch a d20 to decide that.

I'm a proponent of not doing skill checks when (1) they don't matter, and (2) when they make the PCs less awesome, even with a success.

So how would this work mechanics-wise?

Skill Rating

First off, I would probably never do a skill check to operate a "low skill" transportation unless there was some mitigating circumstances. Guy decides to hop on his bike and ride off? Go ahead... Guy frantically jumps on his bike and begins to fumble the ignition while the horse-sized mutant dogs race toward him? OK, that might need a check, but I think in that case the check is more about physically turning the ignition as opposed to being able to steer the bike.

For medium skill one could assume that the PC can put the key in the ignition, but beyond that it might be a little challenging. For example, not everyone can handle driving a Mustang at 120 MPH, even on a straightaway. It's not a matter of maneuverability since you wouldn't be making any turns, it's because you're driving a car with a much bigger engine and a lot more horsepower than you might be physically capable of handling. In this case, whether you make them do a skill check or not is kind of optional and should be decided on circumstance or not.

For hard skill a skill check would definitely be necessary. I may be an experienced driver, but if you put me in the pilot seat of an airplane the best I could do is try to remember the last 15 minutes of Executive Decision ("... Landing gear!!!"). I would need a miracle from the d20 gods to be able to fly a plane.

That being said, if a skill check to determine success or failure in basic driving ability is ever decided upon it should only happen once. Your skill's not going to get worse over time; you're only going to get better. And, short of Tank beaming the training into your skull, you either know how to drive something or you don't.

So, if you think a skill check is necessary...

  • Decide whether you even need, or want, a roll.
  • Use the environmental DC 15/20/25, factoring in backgrounds and whatnot.
  • Rather than deny them the ability to drive, accept that they simply drive really, really badly.

Maneuverability Rating

Here is where it gets entertaining... Like acrobatics, doing something risky in a vehicle has its share of risks and the success depends on the driver's skill and the difficulty of the task.

For argument's sake, let's talk about three maneuvers: a 90-degree hard turn, a handbrake turn and a "bootlegger". Regardless of what kind of vehicle you're driving, each of these has its fair share of risks. Failing a 90-degree turn might not be such a bad thing, but failing a bootleg could up end you or break your steering column.

First of all, not every vehicle can do each of these. An 18-wheeler cannot physically do a bootlegger. It's just not physically possible by definition. So all you people that say "a DM should never say 'no'"... Sorry, but this one's a "no" right out.

Based on that, each maneuver should then have a minimum maneuverability in order to succeed. A 90-degree turn can be done by anyone at any time so it shouldn't require any rating. I don't know if an 18-wheeler can do a handbrake turn, at least not safely, so let's leave that requirement at a medium. A bootlegger should require nothing short of medium, so don't expect to be whipping your 18-wheeler or forklift around like that.

And then there's the difficulty of the actual maneuver. 90-degree turn, easy. A handbrake turn might take a little effort so let's say medium. A bootlegger is hard by any means.

So let's put together what we have so far.

90-Degree Turn
Maneuverability: Any
Difficulty: Low

Handbrake Turn
Maneuverability: Medium or better
Difficulty: Medium

Maneuverability: Medium or better
Difficulty: High

Attempting the Maneuver

So you're behind the wheel and want to do something crazy like a handbrake turn or bootlegger. Time to pick up a d20.

First off you have to determine driver skill. If you're an average Joe, you have no skill so there's no bonus. If you're a professional driver or "wheelman", you should get a bonus, perhaps a significant one if its your own personal vehicle. Let's assume you have the Wheelman profession and are driving your own personal vehicle (or "signature vehicle", as I like to call it... For example, the Interceptor Pursuit Special is Mad Max's signature vehicle; he can do anything in that thing), so you get a +4 driving bonus.

Let's also status Jason "The Transporter, Only Less Greasy" Statham every conceivable bonus as a point of reference.

Now we have to compare the maneuver's difficulty to the vehicle's ability to maneuver. A medium vehicle should be able to do a medium maneuver without much a fuss, but a low maneuverability vehicle like a truck that could still make a maneuver (like the handbrake turn) might have some issues. So if the skill level is higher than the maneuver's difficulty, up the DC by +5 for each step.

One thing to consider is that "low" difficulty shouldn't have a DC at all and start the progression at medium. Therefore "medium" would be DC 15, "hard" would be DC 20, and "legendary" (we'll get to that later) would be DC 25.

Finally, I would think that the skill check would be Dexterity-based simply because it requires reflexes. Let's assume the PC has average Dexterity (+2 attribute bonus).

Using the environmental numbers, here is what we have:

Handbrake Turn: DC 15, DC 20 if you're in a truck
Bootlegger: DC 20, impossible if you're in a truck

Skill Check, Normal Human: +2 Dexterity
Skill Check, Experienced: +4 Wheelman (signature vehicle), +2 Dexterity = +6 total
Skill Check, Jason Statham: +4 Dexterity, +4 Wheelman (signature vehicle), +2 Engineer Affinity, +3 background = +13

An inexperienced driver has a 40% chance of success doing a handbrake turn. That feels high, but PCs are exception after all so things like that might actually be second nature despite never doing it before. A moderately experienced driver gets a 60% chance to do a handbrake turn. Jason Statham can only fail on a natural 1, which can be expected because he's that good, so much so that I wouldn't bother rolling that one. For a bootlegger, the percentages are 25% less, and Jason can succeed doing it 70% of the time which is fairly decent.

This sort of goes back to what I mentioned earlier... If you have an experienced driver behind the wheel, one that no doubt has done his fair share of handbrake turns in the past, why are you even bothering to check if he succeeds or fails? Would you dare insult Jason Statham like that? Give him the benefit of the doubt!

And what would "legendary" be? A bootlegger is pretty impressive and I give that only a "high". Now, if you try a bootlegger while getting shot at and returning fire out the driver side window, of if you actually want to try and aim while you're mid-way through the maneuver, then yeah... I might bump that up to "legendary" if you're crazy enough to try that.


Here are the conclusions:

  • Each vehicle will have a skill rating (which determines how easy it is to drive; checked once) and maneuverability rating (checked when you do something extreme).
  • I cases where there is no chance of failure, or there shouldn't be a failure due to sufficient experience, no roll is necessary.
  • Some sample maneuvers will be provided, just as a frame of reference. Each maneuver will have a description, minimum maneuverability, difficulty and more information if needed. I'm not going to be specific about simple maneuvers like swerving or making basic turns, but people should know what a bootlegger or a J-turn is.

And here are our latest stats, taking this all into consideration:


"Interceptor" Pursuit Special
Medium automobile (1 driver, 3 passengers)
Maneuverability: Medium
Skill: Medium
AC 18     PD 16     HP 54


Handbrake Turn
A quick in place turn where you use the parking brake to slide the back end of the car around a curve, such as when "drifting".
Maneuverability: Medium or better
Difficulty: Medium

A risky maneuver to completely turn a vehicle around 180-degrees while on a narrow highway.
Maneuverability: Medium or better
Difficulty: High

This post got longer than I had anticipated. Stay tuned for Part 3, where I talk about vehicle weapon mounts and, if all goes well, how to put all this into practice.

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  1. Hey I think you did a pretty good job! I just think that Dexterity is not more involved than Wisdom in driving vehicles, if anything could be less involved than Wis. So maybe you could take into account that, by using a mid value between the two, in a 13th Age fashion. 🙂

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