Saturday, July 6, 2013


Basic Role-Playing, the system which underlies Call of Cthulhu, Stormbringer, Pendragon, Runequest and a buncha other games has this mechanic: you have a stat, you try to roll equal or under it.

For head to head contests, there's this system: both parties try to roll as high as possible without going over their stat.

Here is the first point I want to make about this system: it's awesome.

1. It can be explained immediately and easily to new players.

2. It requires no charts to look anything up.

3. It requires no addition or subtraction.  (Here it beats my go-to spot mechanic: both sides roll the same die and you add your whole score.)

4. (Therefore) You immediately know if you succeeded or failed.

5. It can work on ability scores scaled to any die (You could build a game where your stats ranged 1-10 and roll a d10 and it'd still work). Which means you could use it in any system that rates abilities in numbers of any kind.

6. It respects high scores in detail--for every pip your score goes up, your chances get a little better. So you can use it in a campaign-oriented game where PCs slowly improve by steps.

7. It has a degrees-of-success system built in: there's fumble (rolling the max score), failure (rolling over), weak success (rolling under but not better than the other guy or--with a slight hack--a static opposing target number), success (rolling under), mega success (rolling exactly your score).

8. It requires no derived numbers. Like a score of 17 is a score of 17, not 17 (+3) or 17 (+1). (Like, ok, a lot of non-D&D systems.)

For some reason, despite all the intertalk you hear about folks clinging to various old D&D rules purely out of nostalgia even when the rule in question is patently useful, folks rarely bring up the fact that this rule pretty much beats the hell out of D&Ds: d20-add-derived-numbers-roll-high-meet-a-target-number (and sometimes also roll under or roll a d6 trying to meet a derived number instead).

Why? Because nearly everyone who would make it is either still using the d20-roll-high system (WOTC D&Ds keep it) or is using some other less-elegant system that, if we're honest, is probably only still being used (if it was invented before BRP) out of nostalgia or (if it was invented after BRP) out of pure neophilia or just a desire to avoid a lawsuit from Chaosium.

The system has, for all the parameters above, never been beat. Lots and lots of games don't use it--very few don't use it for any kind of good reason.


It does have two drawbacks I can immediately think of:

1-You don't try to roll as high as possible. People like that 00 or 20 means something good. Or at least they seem to.

2-Not every player is trying to hit the exact same set of numbers when they roll, so you can't add bonus fun where you key the die roll to a table where, say 1 always means This and rolling your score always means That and rolling 15 always means The Other Thing.


(Here's a roll-high variant that solves both of those problems: you try to roll as high as possible. If your roll is lower than your score in the relevant stat, you get to roll again, once. It creates new problems--the most obvious one is possibly having to roll twice. It'd work well for something like DCC spell checks.)


(Some of you may be eyeballing "Roll as high as possible or take your stat, whichever is highest" but that's a drag because basically if the GM wrote the adventure, the GM knows in advance if the PC will win any contest with a static target so you're basically just deciding what will happen when you write the adventure.)

Another observation:

I've played games that work the BRP way, and then, hours later, played games with less elegant resolution systems. Y'know what? You don't much notice the difference in play. At a certain point these things just don't matter that much. I mean: if you were building a language from scratch you probably would spell "would" differently---but it works out alright anyway.


S. P. said...

Unknown Armies is my favorite game for exactly this reason. It's ultimately just a gussied-up Basic Role-Playing.

Jomo Rising said...

I love BRP, and would use it in my fantasy game, if my players didn't like the classic "Level Up" of D&D. Has someone mastered the Level Up feel in a BRP game?

Talysman said...

There's two other problems with the BRP system you may have missed:

1. Perhaps this changed in some BRP-based games, but the ones I remember playing/reading had "max success" as a 01, not an exact match of the ability score. This is a feature that it shares with GURPS and The Fantasy Trip; you want to roll high *and* roll low.

2. The skills are d100-based, but the ability scores are in the standard 3d6 range and only sometimes are used as straight d100 target numbers. Other times, you have 5 x INT or 3 x DEX targets, or (the old contest of skills approach) you had a table to compare ability scores and look up a target number (based on 50 +/- (5 x difference between scores).)

The pure version you describe isn't too bad, though. Although personally, I'd like to take the Fantasy Trip approach and use 3d6 score range, base 3d6 roll under, drop or add dice for more difficult tasks, and modify it the way you suggest (roll higher than opponent, roll exact match for max success, maybe use all 1s for something else like "success with side effect".)

Zak S said...

2: When I run BRP I just have people roll d20 (maybe modified) instead of 5x whatever. We have these d20s around, might as well use them,

Random Wizard said...

That is a good point. Most games that I have seen, when they take on a skill system, tend to focus on building up skills as the way to increase power; Star Frontiers, Top Secret, BRP.
D&D is a different beast where a lot of the complexity is wrapped into gaining a "level" and then putting skills into classes.
I have written some posts that compare different task resolution systems to "roll under percentages"; FUDGE, FASERIP, d20
What you ask can be done by simply converting d20 system into %100 as it would entail 5% increments. I will have to write a post on it.

Wil McKinnee said...

This might be inappropriately lengthy...

but it's something that has been brought to question in my own house for the past couple of days, because my players like the Level-Up system as well and it's for the same reason that Zak mentions the affinity for rolling max on a d20. 20's bigger than 1.

My impression is that BRP encourages an emphasis upon the idea of 'Procession', as opposed to 'Progression'. Like, to 'level-up' would imply that one has the mindset of developing a character according to what they might 'expect' to experience whilst in their hostile, little world.

I think that there is also required some endowment for leveling-up in general. The distribution of skill points, bonuses, ability mods, etc. And these things don't necessarily have a distinct relationship to what the characters experience. The points are given to aspects of the character according to what they 'want' to be good at and not always what they 'need' to be good at. (Next comments are referencing Cthulhu as a counter) I like creating characters in BRP because 'what' I want to be good at is what I am good at according to my character alone, and what my character is confronted with will determine where the development needs attention. But then again, I think that this particular form of character creation results in an 'identity' that will learn where to employ its 'function' in due process of recurrent game-play (adding points here and there as it applies to the context), while a system that levels up will produce characters who start as entities with potential 'functions' but develop their 'identities' through in-game activity.

And I don't mean to wax neurotic on this subject, but it is sometimes difficult to get players to shake the desire for a measurable type of achievement.

I ran a solo session with my significant as Keeper the other evening and we discussed the differences between how the rolling of dice sort of conceptually operates between BRP and D&D, specifically. In D&D, the event in which a PC is regularly unsuccessful on account of bad rolls can be countered with knowing over time the player will eventually be able to bolster this particularly weak aspect of the PC with the distribution of earned points. There is comfort in knowing, if I can just survive three more weeks then I'll be better at climbing shit. And I just can't see BRP offering that sort of thing. When you fail at rolling out a skill using elegant resolution, it's because at this precise moment of action, your character simply failed to rise to the occasion: failed to deliver. And what makes this so frustrating sometimes is that it isn't always a result of or influenced by an external, opposing difficulty.

So, if you're bad at climbing... then get better at climbing. And yeah, that's not exactly positive substantiation that you'll ever be good at climbing unless the appropriate play-time is spent in dedication to upping your game, which requires a different kind of attentiveness towards how the game is played out, in my opinion.

Now, my ideas could very well be totally off-base, but as it currently stands I don't see how BRP could produce the same kind of escheloned style system of levelling up, not in the 'classic' sense anywho. What it does present, however, is a more intimate relationship between the player and their available abilities. And I don't see anything wrong with that.

I'm running 'Death Frost Doom' tonight but using BRP created characters instead of LoTFP.

Could be a horrible idea.

Talysman said...

That's a good work-around. But what do you do about the ones that say 2 x or 3 x stat? Or do you just drop those, since there was no good reason to include those anyways?

Zak S said...

Just do it like it was D&D--roll under with a negative or positive modifier.

Chris Hogan said...

Fading Suns used almost exactly the system described above (d20 roll under, closer to stat = better, equal to = crit), but then muddied the waters with an extra derived Success Points/Dice mechanic which mucked up thumbnail probability guesstimation no end even before you got into *shudder* Accenting (deduct from/add to the initial die roll to get less/more successes). A good game ruined by a tendency to keep slathering on more and more stuff of less and less actual utility.

(Odd, but I always thought the BRP crit rule was 1/10 of skill or less = crit. When was that changed?)

Zak S said...

BRP has more than one subsystem. In the d100 rolls, really high is a fumble and really low is an impale and there's also a 1/10th skill roll but then ALSO in the Pendragon 20pt skill system there's the roll-equal crit.

The mechanic is elegant. The system(s) less so.

Still, they work.

faoladh said...

As a note of gaming history, the first game (I believe) that used the blackjack system of rolling was Pendragon. That was a modification of the original BRP system, anyway, so it was easy to back-port it when Chaosium decided to revamp BRP. Pendragon managed to avoid the mess of mixing various types of rolling by discarding direct compatibility with the more strictly BRP games.

Tedankhamen said...

I agree that BRP's d100 mechanic is elegant, but the system is decidedly not, for a few reasons.

Size seems like an attribute that could be dropped without any harm and replaced with D&D style descriptors (Man size, Large, Tiny) affecting damage and dodging/being hit.

Also, BRP has developed skill point allocation in such a way that the skill percentiles have become divorced from attributes, which are basically pointless except for the rare attribute roll. Although the Stormbringer 1e system of skill bonuses derived from attributes was admittedly clunky, using attributes as defaults for skills and allocating skill points based on Education if CoC would have made attributes more relevant.

Zak S said...

Yeah that's why I wrote about the d20 and d100 mechanics and not about the system.

Tedankhamen said...

Sure, I get that. Just noting that the elegance of the d100 and opposed rolls is marred a bit by the system it is bolted to. Just like when D&D thieves skills were all d100 and nothing else was. People found it jarring.

I still prefer d100 over the difficulty check for the reasons you gave. By the way, I don't use the d20 for attribute check, although it's a good and simple idea. Instead, I have players roll attributes x 1-6 depending on difficulty. I know, more math but somehow satisfying. As you note, d100 allows people to fiddle easier to adjust to taste. Hard to do with DCs and to hit rolls.

Brandes Stoddard said...

How would you handle variable task difficulty without creating a need to add and subtract from either the die roll or the target number? It sounds like this mechanic is beautiful until someone tries to implement it in an actual game. God knows Pendragon had bizarre task-resolution problems once your score passed 20.

Zak S said...

Variable task difficulty?

"For head to head contests, there's this system: both parties try to roll as high as possible without going over their stat."

Or simply set a target number. So you have to roll over the target number and under your stat.

And in some cases you _would_ have to add or subtract (like if you were blinded) but at least you don't have to add or subtract just to do the basic mechanic.

Sine Nomine said...

The problem is that you're either A) always going to be modifying the roll to give PCs a semi-reasonable chance of succeeding or B) starting out PC ratings in the 60%+ zone to get a player-acceptable rate of success. It's like the old WHFRPG 1st edition issue with succeeding on skill checks- the GM basically had to tack on 20 or 30 percentile points to any given roll if a new PC was going to have a tolerable chance of succeeding.

Of course, you can flatly banish modifiers from all but the most exceptional skill rolls, in which case you've got a situation B, because players tend to get frustrated even at 50/50 odds.

Flat percentile rolls can be useful tools, but I like a bell curve too much to go for them myself.

knobgobbler said...

One of the things I like about BRP is that it is generally more unforgiving of violent stupidity than a system like Savage Worlds. Having 50/50 odds doesn't bug me because I'm only going to be rolling in the most stressful situations (which I'm going to be trying to avoid, hopefully).
Having the game heavily front-loaded to insure my character's success just ends up feeling like masturbation to me.

JDJarvis said...

Zak, you do describe an elegant system but not the core system used in BRP (at least not the big giant book from 2008).
The higher degree of success wins a skill contest not the highest die roll.
success: <= chance, special success <= 20% or chance, critical success <= 5% of chance. Success beats failure, special success beats plain old success and critical success trumps all. If both have the same degree of success the higher dier roll is the winner.

Zak S said...

You have accurately grasped that I am not describing the system in the giant book from 2008.

The system's used in Pendragon for the 20pt skills.

Robert Fisher said...

I really like the Pendragon/black-jack system. Although, with D&D, I’d want an option to include level. Ability + level is a possibility, but I dunno.

I also go back-and-forth between linear & normal distribution. I tend to think linear works better for lots-of-rolls systems like combat while normal tends to work better for the one-roll things that ability checks are often used for.

Antonio said...

Pendragon is definitely the best of the BRP iterations, managing to do everything with a d20 and d6.

Antonio said...

WEll, starting at least from Stormbinger 1e and going through RuneQuest 3e, and the latest Yellow Book BRP, attributes DO modify skills. It's only in CoC that there is no tie except for EDU, but that's quite easy to remedy, since CoC gives skill categories anyway.

Antonio said...

Dragon Warriors uses exactly such a system; depending on the task, you either roll 2d10 (bell-shaped distribution) or d20.

faoladh said...

I would not disagree, or at least not strongly.

Banesfinger said...

In theory, everything you say is true: it is a much more elegant system.
But my players HATED it compared to d20.
In their minds, a 30% chance (d100) to hit "sucked" but getting +6 on a d20 roll was great! The math was equal, but the "perception" was different...

Viktor Haag said...

Harnmaster had a wonderful addition to the basic percentile system used by BRP -- dead-easy and quick calculation of exceptional results: ANY roll that ends in a 5 or a 0 is exceptional.

- If you succeed at your roll, and it ends in a 5 or 0: congrats! critical success!

- If you fail at your roll, and it ends in a 5 or 0: look out! critical failure!

This had the hallmarks of elegance: easy to explain to players, zero math required, dead-easy to deploy at the table with no lookups, not perfect but reasonably scalable with different levels of character ability.

Antonio said...

That's quite clever! Sort of compressing information into just one die roll. Something similar does the recent 13th Age.

Ynas Midgard said...

A Hungarian game, Codex, used a similar resolution for combat. There were two stats, Attack and Defense, both around 30-90. The attacker rolled a d100:
- if he rolled under his Attack, the opponent's Defense decreased as per damage
- if he rolled under his Attack AND above the opponent's Defense, he scored HP damage (and decreased Defense as above).

(Not related to the subject, but the damage roll was actually not a separate roll but one derived from the attack roll and the situation, thus determining if the lower, higher, or both dice were used as damage.)