How much math should RPGs require?

[pemerton]

I recall (it's 2 decades ago, so hopefully this is at least roughly accurate) that Rolemaster applied penalties to pretty much every roll if you were injured.

Some of the people I played with would keep a track of the most severe penalties their PCs had been subject to. One Elven Moon Mage had found himself below -200 at least once or twice!

 

[GMMichael]

In fact I still recall one optimist player, whose character had a spinal injury (-50 I believe) plus low hits telling me "it's OK, so long as I roll high I should be able to block the door with stone". He did not roll high.

Is it straight-line percentile? I have a slight problem with rules that impose incompetence on competent characters, i.e. swingy die rolls. This gets into the game designer's math responsibilities. Fireball-blowing-up-in-face is great for low-level mages (well, not really) but I'd hope rolling rules make an accurate representation of just how likely this is to happen to a more experienced mage, if at all.

Disadvantage is a good mechanism for modeling declining abilities. No subtraction needed. I can also see the removal of bonuses (versus the addition of penalties) as a way to keep maths down while conveying the concern of character health loss.

 

[Thomas Shey]

I've noted that most in-combat penalties from damage are, in actuality, unrealistic. Whether that concerns you is in the eye of the beholder, but if it doesn't, you at least need to ask what purpose its serving.

 

[Celebrim]

I've noted that most in-combat penalties from damage are, in actuality, unrealistic. Whether that concerns you is in the eye of the beholder, but if it doesn't, you at least need to ask what purpose its serving.

Realistic or not, in terms of gameplay combat death spirals are just not very engaging and crippling characters after combat such that the player is effectively out of the session isn't great either. Realism for its own sake rarely makes for interesting game play or interesting story.

My preferred system is a homebrewed modified version of 3.0e and it does add a 'Staggered' condition with a major downside (you can only take one action a turn) but that only kicks in when you are at 10% or less of your hit points - think about how rarely that happens at low levels. It adds to me a cinematic feel of the character nearing death as they progress through increasingly bad negative conditions close to zero hit points, and it's resulted in some great combats where players have to make interesting tactical decisions to protect a colleague and keep them in the fight or alive, but I wouldn't want it to occur more often than it does. Having it add occasional tension to a fight is one thing, but regularly gimping characters just for realism's sake isn't that great and even in D&D I probably wouldn't have a "you've been wounded" consequence except that D&D makes healing comparatively available and low cost.

Like many realistic things I once wanted - languages, currency, numinous magic - injuries are something I've discovered needs to be confined to narrow areas for gameplay reasons.

 

[prosfilaes]

David Pulver said that he was told that GURPS Vehicles specifically couldn't use cube roots or logarithms. So there's tables like 1-9: 0, 10-99: 1, 100-999: 2, 1000-9999: 3 and literally "so on", which is a logarithm base 10 in table form.

That certainly wouldn't have bothered me, but GURPS Vehicles overwhelmed me with the amount of calculations. There's applications to create a vehicle using the system, and I'd definitely use them. Same thing with tabletop; I could deal with integer cube roots or logarithms at the table, but the +1 bonus from bless and the +1 dodge bonus from the ring and +2 dodge bonus from this and +1 circumstance against humans and what all is in play and what stacks and what doesn't gets overwhelming.

 

[Cordwainer Fish]

David Pulver said that he was told that GURPS Vehicles specifically couldn't use cube roots or logarithms. So there's tables like 1-9: 0, 10-99: 1, 100-999: 2, 1000-9999: 3 and literally "so on", which is a logarithm base 10 in table form.

See what happens when grade schools don't teach how to use a slipstick any more?

 

[Gorgon Zee]

Is it straight-line percentile? I have a slight problem with rules that impose incompetence on competent characters, i.e. swingy die rolls. This gets into the game designer's math responsibilities. Fireball-blowing-up-in-face is great for low-level mages (well, not really) but I'd hope rolling rules make an accurate representation of just how likely this is to happen to a more experienced mage, if at all.

Disadvantage is a good mechanism for modeling declining abilities. No subtraction needed. I can also see the removal of bonuses (versus the addition of penalties) as a way to keep maths down while conveying the concern of character health loss.

Rolemaster has more of a middle-earth feel, so spells like "fireball" are not common at all. Low-level mages won't have them.

If you are casting a spell at or below your level, and you have no reason why you should fail, no roll is needed. It's only if you're hurt or overcasting that you need to roll. And even then, if the spell is not inherently dangerous, or you have a lot of skill, it's not likely to fail.

In many game systems I run magic is risky; for me that feels more natural to have an expectation of a chance of failure. Disadvantage has always seemed a very coarse mechanism for penalizing. Should a player at half hits be disadvantaged the same as a player who is paralyzed and casting a 10th level spell when they're 5th level? I like disadvantage for simple systems where you don't want to bother considering many factors, but that's not really where Rolemaster is aimed.

 

[Willie the Duck]

David Pulver said that he was told that GURPS Vehicles specifically couldn't use cube roots or logarithms. So there's tables like 1-9: 0, 10-99: 1, 100-999: 2, 1000-9999: 3 and literally "so on", which is a logarithm base 10 in table form.

That certainly wouldn't have bothered me, but GURPS Vehicles overwhelmed me with the amount of calculations. There's applications to create a vehicle using the system, and I'd definitely use them. Same thing with tabletop; I could deal with integer cube roots or logarithms at the table, but the +1 bonus from bless and the +1 dodge bonus from the ring and +2 dodge bonus from this and +1 circumstance against humans and what all is in play and what stacks and what doesn't gets overwhelming.

Young adult math geek me loved GURPS Vehicles when it first came out. You could calculate and re-calculate the cost or fuel expenditure or performance of your spy car or futuristic tank based on before and after you added an extra 5 points of DR onto the armor (or if you included cramped or spacious control stations). You could do the same 'more DR, or more HP?' type questions you could with character creation, but also add the wrinkle of 'but what if I up-spent and got the ultra-light-weight version of on or the other?'

I remember deciding that my futuristic space station's escape pods needed months of supplies instead of weeks (because anything that would cause you to abandon ship for it likely meant that anyone who might rescue you wasn't in-system). Thus the size of the pods had to be modified and the fuel they contained as well. And because of the weight and size change of those, the whole station had to be redesigned and calculated and decisions made to maintain certain performance goals given certain budget limitations. On days when I was looking for ways to put off college homework, this was a great product.

A few things happened.

1. I no longer am looking for ways to take more time to do my not-at-the-table-with friends part of TTRPG gaming.
2. I have a job which more than covers my need for minutia.
3. I realized, at some point that, after all the calculations were completed, the vehicles often boiled down to a semi-brief list of stats and performance metrics (approximately the same as a PC and their basic gear, plus some extra movement functions like handling and acceleration). The only thing all the extra hoops did was give a more complicated way of determining those values, but didn't, in and of themselves, make the values more exciting.
4. I noticed that, as complex as they made things, simple qualities that differentiate real world vehicles (or that you might want in your game-world vehicles) aren't available. You can vary your drive-train and power plant wattage and total vehicle weight, but you can't vary torque. It's hard to make a pickup truck which can haul an immense load which can't also go 180 MPH when unloaded. It's hard to make two F-Zero racecars -- one with a higher top speed but low acceleration and another with the reverse. If you can't accurately model reality, and you can't make distinctions between vehicles which would make you choose one over the other, then what exactly is the point?

The last part there being key, and kind of the point I keep making on the subject. For me, the math can't be there just for it to be there. It has to serve a larger point (and then, the point has to be one I consider actually valuable to the gaming experience).

 

[aramis erak]

See what happens when grade schools don't teach how to use a slipstick any more?

When I was teaching 6th grade, I showed them how to use one...
I also just showed my math-phobic adult offspring how to use prefix notation and postfix notation to make doing math easier, and showed them the HP-48G emulator.... and how to use it.

 

[Hattly82]

Linear algebra is probably the lower limit. Differential geometry for anything where the curvature of spacetime becomes important. Point set topology will usually be overkill.


But I’ve found that when you're working on interdisciplinary projects, it gets tricky fast. I was once knee-deep in an economics-related project that required applying linear algebra concepts.

I didn't expect that crossover at all. It made things feel overwhelming, so I decided to use https://essays.edubirdie.com/economics-assignments to get help with the economics portion. It was a lifesaver and really opened my eyes to how connected different areas can be.

I think linear algebra might be too much for most players. Most RPGs should stick to basic arithmetic—addition and subtraction work well for hit points and damage. Adding layers of complexity, like differential geometry, could alienate casual gamers. Many just want to enjoy the game without doing complex math. It’s all about balance.