The Resolution System¶
This document is part of the Frontiers Design Documentation, a set written to teach instead of to instruct. Each entry takes one design problem, explains what that problem is in the wider language of tabletop design, surveys how games have solved it, and then shows what Frontiers does as one worked answer among many.
It is written for several readers at once:
- Designers using Frontiers who want to understand why it works the way it does.
- Designers using Frontiers who want to change it, and need to know what a change will cost.
- Designers building something else entirely, who want the design space mapped before they choose.
Frontiers is a toolkit, and a toolkit is only useful if you can see what each tool is for. None of this is a rule; the rules live in the Rulesets, and what follows is the reasoning, the history, and the alternatives.
There will be terminology here that is unfamiliar to casual players. Treat this documentation as advanced content, written for designers interested in building. It will not teach you every term or phrase it uses, but it will do its best to define them as they arrive.
What is Resolution¶
Here's another one that's no fun at all to design and matters a lot anyway.
A resolution system is how a game turns an uncertain attempt into an outcome. When a character tries something that might not work, resolution is what decides whether it did, and it's the one subsystem every single action passes through. You'll touch it more than any other rule in the game, hundreds of times a session, which is exactly why it is so easy to underrate while designing and so impossible to ignore while playing.
Resolution answers two questions, and they're worth separating:
- How does an attempt become an outcome? The mechanism. What you roll, what you compare it against, and what shape the randomness takes.
- How is success divided from failure? The verdict. Whether the answer is a plain yes-or-no, whether there are degrees, and where exactly the line falls.
Almost every other rule in a game is content poured into the frame those two questions build. Answer them well and everything downstream has solid ground to sit on; answer them badly and no amount of good content saves it, because the wrongness is felt on every roll.
Why Resolution matters¶
Resolution sets the feel of a game more than any other single system, and it does it below the level most players consciously notice.
Consider what the mechanism alone decides. A flat die, where every result is equally likely, makes a game swingy: the underdog always has a real chance and the expert is never safe, and play feels volatile and exciting. A curved system, where results cluster in the middle, makes a game dependable: competence holds up, upsets are rare, and play feels earned and stable. Neither is better. But a designer who picks one without noticing has chosen the emotional texture of their entire game by accident.
The verdict half matters just as much. A binary system, pure success or failure, is fast and stark, and every roll is a coin's edge. A system with degrees, where you can succeed at a cost or fail forward, is richer and slower, and turns every roll into a small story. Again, neither is correct, and again, the choice colors every moment of play whether the designer meant it to or not.
This is the trap of resolution. It looks like plumbing, a technical decision to be settled quickly so the interesting design can begin, when it's in fact the thing every other decision flows through, and its character becomes the game's character. You should choose it deliberately, knowing what each option does to how the game feels in the hand.
Every roll in your game passes through this one system. What do you want that moment to feel like?
The Approaches¶
Resolution is a broad design space, but almost all of it comes down to how a system answers the two questions: how an attempt becomes an outcome, and how success is divided from failure. It's more useful to understand the forces at work than to catalogue every game, so what follows is organized by idea, with systems named only as evidence.
The mechanism: what shape is the randomness?¶
The single most consequential choice is the shape of the random element, because that shape is what a game feels like before any other rule is added.
Flat randomness gives every result an equal chance. A single die is the clearest case, and Wizards of the Coast's 5e SRD lineage is built on one. The effect is volatility: skill tilts the odds but never secures them, the weak always have a puncher's chance, and the strong are never safe. This is why single-die games feel exciting and unpredictable, and also why they can feel arbitrary, since competence is only ever a thumb on the scale.
Curved randomness clusters results toward the middle, and it arrives the moment you add dice together. Roll two or three dice and sum them and the extremes become rare while the average becomes common. The feel flips: competence becomes reliable, upsets become real events rather than routine noise, and the game rewards being good at something with actually being good at it. Steve Jackson Games' GURPS on 3d6, and any 2d6-summed system, live here. The cost is excitement at the edges, since the wild swing a flat die offers is exactly what a curve suppresses.
Dice pools ask a different question again. Instead of one number, you roll a handful of dice and read them as a group. Some pools count how many clear a bar, as Catalyst Game Labs' Shadowrun does, so competence adds dice rather than adding to a total, and a skilled character rolls more chances instead of a higher number. Others read the best die: Evil Hat's Blades in the Dark builds a small pool of d6 and looks only at the single highest, where a 6 is a full success, a 4-5 is success at a cost, and anything lower fails. Either way, a pool feels dependable in a way a flat bonus does not, because it's many small hopes rather than one large one, and pools tend to produce degrees for free, since the count or the top die already says how well.
Split dice pull the two halves of a roll apart. Tomkin Press's Ironsworn rolls one action die against two separate challenge dice, and the verdict is how many of the two you beat: both is a strong hit, one is a weak hit, neither is a miss. The mechanism itself produces three graded outcomes without any margin arithmetic, because the structure of the roll (one value measured against two) is doing the grading. It's a reminder that degrees don't have to be read off a single number; they can be built into the shape of the throw.
What sits under all of these is that no mechanism is neutral. Before you write a single skill or ability, the shape of your dice has already decided whether the game is volatile or dependable, and that decision is felt on every roll for the life of the game.
The verdict: how sharp is the line?¶
The second question is what the mechanism's output means, and the range runs from a hard binary to rich gradients.
Pure binary asks only "did you meet the number." You succeed or you fail, outright, and the game moves on. This is fast and stark, and it keeps every roll tense, since there's no soft landing. Much traditional play works this way, and its virtue is speed: the answer is instant and unambiguous. Its cost is that a hair's-breadth success and a triumphant one read identically, and so do a near-miss and a catastrophe.
Degrees of success ask "how well," not just "whether." The margin between the roll and the target becomes information: beat it by a lot and something extra happens, miss by a little and you fail softly. The percentile tradition, Chaosium's Call of Cthulhu among them, reads success bands off the same number that decided the roll, so degree costs nothing extra to determine. Degrees make every roll a small story rather than a switch, at the price of a little more to interpret each time.
The mixed result goes furthest, and Lumpley Games' Apocalypse World family is its clearest expression. A roll can land on success, failure, or a middle band where you get what you want at a cost, or fail in a way that moves the story forward. The Forged and Ironsworn lineages build their whole feel on this middle band, often making it the most common result instead of an edge case, so most rolls land somewhere in between instead of settling the question outright. This turns the verdict from a line into a spectrum, and it changes what failure even means: a failed roll isn't a dead end but a complication, a door opening as another closes. It is the richest verdict on offer, and it asks the most of the table, since someone has to author the cost or the complication every time the dice land in the middle.
The same holds here as with the mechanism. Choosing a verdict is deciding how much meaning a single roll carries, and that choice sets the pace and the texture of play as surely as the dice do.
The two choices combine¶
The useful insight is that these two axes are independent, and a game's whole resolution character is the combination. A flat die with a binary verdict is fast and swingy, the classic pick-up-and-play feel. A curved sum with rich degrees is dependable and story-heavy, slow in the best way.
A dice pool splits the difference, offering reliability and built-in degrees at once. No corner of that space is the correct one; the question is which matches the feeling you're trying to build, and the honest work is choosing both axes instead of inheriting a familiar pair without noticing you had a choice.
Resolution in Frontiers¶
Now, with that overview to catch you up to speed, here's the approach Frontiers takes and the reasoning that led there. This is the one subsystem where Frontiers does not give a single answer. It gives three, and the point of this section is why those three are one design instead of three.
The shared spine¶
Underneath all three rulesets is the same resolution act: roll against a target. You roll, you compare to a number, you meet it or you don't.
This is deliberately the plainest thing it could be. Rolling against a target is the most forward, least fussy way to resolve an attempt, it takes no explaining, and because it's consistent, a designer can build on it without relearning how resolution works each time. It's also open at the edges.
Nothing stops a system from adding rolls to defend, contests, or a different comparison entirely; the spine is simple so there's room to extend it. Frontiers picks the humble option, because an engine's base layer should be the thing everyone can agree on and nobody has to fight.
On top of that spine sit three constants that make a roll recognizably Frontiers no matter which die you use: a Gradient for how well it landed, Favor for circumstance, and the option to take your Score: settle for the flat number your character is reliably worth, rather than rolling for the chance at more. Those three travel across every ruleset. What changes is only the dice underneath them.
Three expressions on one scale¶
The three rulesets sit as three points on a sliding scale rather than as rivals, running from classic to tactical, with Frontiers' own opinion in the middle.
- The d20 leans classic. A flat die, familiar to nearly everyone, swingy in the way people expect a d20 to be.
- The d100 leans tactical. A roll-under percentile scale with room for real numbers, where circumstance and competence are exact and play is granular.
- The d18 sits between them, and it's Frontiers' actual method: the curved, opinionated middle that trades the d20's swing for reliability without going as far as the d100's granularity.
There are two reasons to ship all three instead of picking one. The first is that I build official systems on this engine, and I don't want every one of them to feel the same. Handing myself three resolution feels is how a Frontiers horror game and a Frontiers tactical game come out different instead of reskinned.
The second is the message it sends to everyone else: the dice are meant to be swapped. Offering my own three, plus leaning on the two most familiar dice in the hobby, means a designer can hook onto whichever one already matches the game in their head, and trust that the rest of the engine will still fit.
The Gradient, at three depths¶
The Gradient, reading how well a roll landed and not only whether it succeeded, is the piece Frontiers is proudest of, and it's the clearest answer to the question every new engine has to face: what makes this different from rolling a d20 like always? Degree-of-success, treated as a first-class part of every roll instead of an afterthought, is a large part of that answer.
But I know not everyone wants it. Some tables find degree-of-success a chore, and an engine that forced it would be picking a fight it doesn't need to pick. So instead of mandating the Gradient or dropping it, Frontiers integrates it at three different depths, one per ruleset, and that difference is a feature:
- On the d18, the Gradient is welded in. The same die that decides success is read again for degree, so the two are one act, and it feels integral because it is. This is the Gradient at its best. The weld produces a real but moderate tilt rather than a lockstep: at DT 12 unmodified, a success reads Positive about 48% of the time against Negative about 19%, and a failure reverses that. The
1d12carries most of the sum's variance, so the1d6colors the verdict without dictating it. - On the d20, the Gradient is tacked on. A separate die, rolled alongside, optional. A table that doesn't want it simply never picks it up, and nothing else changes.
- On the d100, the Gradient falls out naturally. It's already sitting in the units die of the percentile pair, there whether you look or not. Remove the rule and, again, nothing else moves.
The spread is intentional, since different tables want different amounts of this idea, so each ruleset offers a different level of commitment to it, from load-bearing to removable. It's also part of why the d18 is the recommended form: the Gradient is the soul of Frontiers, and it feels best where it's welded instead of bolted on, so the version that welds it is the version I point to first.
Favor with generous math¶
Circumstance is expressed as Favor and Disfavor, an extra die kept high or low, instead of as numeric bonuses. The reason is plain: it's the easiest math to balance in an engine meant to be built on. A number has to be sized, and sizing situational numbers correctly is one of the hardest things in system design; a die of Favor is always worth roughly the same amount, so a designer can hand it out without doing arithmetic about whether this bonus is too large.
This doesn't ban numbers. A system that wants numeric modifiers can use them, and the d100 leans on them openly, because a hundred-point scale has the room. But the engine doesn't lean on them by default, because they're familiar and comfortable right up until you have to balance a pile of them. Favor is the safer foundation, and safe foundations are what an engine owes the people building on it.
Initiative follows the same idea¶
Initiative gets no special theory. Frontiers has a passive-assurance philosophy running through the whole engine (take your Score for certainty, or roll to reach past it), and Initiative simply extends that to turn order. You can take a flat, reliable Initiative and know where you stand, or roll for the chance at more and the risk of less. It's the resolution philosophy applied to one more number.
Is this the best answer?¶
Honestly, resolution is the subsystem I'm least willing to call finished, and the Gradient is why.
The spine is solid, and the three expressions do what I want. But the Gradient is hard to get right, and I don't think anyone has fully solved degree-of-success, me included. It isn't flawed so much as dependent. Much like the language rules many games ship and few tables ever invoke, its value comes down to whether the GM and the system designer actually reach for it.
Lean on it and it sings, ignore it and it withers, so it never quite behaves like a self-contained mechanical slot-in that works the same at every table regardless of attention. I'd rather say that plainly than pretend otherwise.
That dependence is baked into the design rather than papered over. The three depths exist for that reason: I expect varying levels of engagement with the Gradient, and the d18 is recommended because it's the form where the Gradient carries its own weight instead of asking the table to carry it. I fully expect official Frontiers systems, and the systems others build, to keep modifying and extending it, because it's a good catch-all idea that's nowhere near exhausted.
So no, none of this is the last word on resolution. What it is instead is a strong spine, three honest expressions of one philosophy, and one open question I'm handing to you along with the tools to answer it. The final section below sets out variant and alternative rules you can use in place of any of it, along with what each one changes and what it will cost you elsewhere.
A note before the changes¶
Resolution is different from every other subsystem here.
Everywhere else, the engine gives one design and a menu of ways to change it. Resolution gives three finished designs (the d18, d20, and d100, each one handcrafted and balanced), and those three are already the main answer to "what if I want a different resolution feel." So this section is shorter than the others on purpose.
Changing resolution meaningfully means either tuning within one of the three rulesets, which is straightforward, or replacing the spine wholesale, which is the single most disruptive thing you can do to the engine, since nearly everything else targets a number that the spine produces.
I'll be honest about the ceiling. If you want a resolution system unlike these three, I can't hand it to you. You'll have to design it, which means deciding for yourself how you want every roll in your game to feel, and then rebuilding everything that depends on the roll to match.
What I can offer is the three I have fostered, the Variants below for adjusting them, and the promise that if I craft more resolution forms in future modules, they'll show up as options too. These three are simply the ones I chose to polish for the core.
Variants¶
Variants tune a ruleset you've already chosen. These are safe and expected.
Tune the Gradient¶
The Gradient is the most adjustable thing in resolution, and the rulesets already show it at three depths.
Change its depth¶
Weld it, tack it on, or let it sit incidental, regardless of which die you're using. A d20 game that wants the Gradient to matter more can read it as integral instead of optional; a d18 game that wants it quieter can loosen the weld.
For instance, a d20 game can stop treating the 1d10 as optional and call for it on every roll, which turns the Gradient from something the table may ignore into something it reads every time.
Change the bands¶
Widen or narrow what counts as a Positive or Negative result, or add finer tiers, exactly as each ruleset's own Gradient section lays out. More bands is more texture and more to read; fewer is the reverse.
For instance, reading the 1d6 as edges only, 1 Negative, 2–5 Standard, 6 Positive, keeps the Gradient quiet until it spikes, where the default even thirds have it saying something on four rolls in six.
Remove it¶
Cut the Gradient for a pure success-or-failure game. On the d20 and d100 this is a painless deletion; on the d18 you lose the piece the ruleset was built around, so if you're cutting the Gradient, the d18 is probably not the die you want in the first place.
For instance, a d20 game that drops it simply never picks the 1d10 up, and nothing else on the sheet changes.
Tune Favor¶
Favor is the circumstance tool, and it has a few honest dials.
Change the cap¶
Allow more or fewer stacks of Favor and Disfavor. More makes circumstance swingier and situations matter more; fewer keeps rolls closer to raw competence.
For instance, capping each side at 1 instead of 3 means high ground and a distracted target stop stacking into something close to a guarantee.
Lean into numbers¶
Add numeric modifiers alongside Favor, or in place of it, for a more tactical, granular feel, essentially moving a d18 or d20 game toward the d100's numeric temperament. This buys precision and costs balance, since situational numbers are the hardest thing in the engine to size well.
For instance, handing out a flat +10 where you would otherwise have granted a die of Favor, which on a d100 Routine Target of 50 is worth about +25.
Alternatives¶
Alternatives replace the spine, and every one of them reaches into the entire rest of the engine, because Defenses, difficulty numbers, contests, and every derived target are all built to be rolled against. Treat these as the start of building your own system rather than as drop-in swaps.
Change the reading direction¶
Flip a roll-over ruleset to roll-under, or a roll-under one to roll-over. This reshapes the entire feel of the game, and it's less a tweak than a redesign, since every target number in the engine is written for a particular direction. The d100 already demonstrates roll-under done properly; use it as a reference instead of converting a d18 or d20 by hand.
Leave the spine entirely¶
Swap "roll against a target" for a fundamentally different mechanism: a counted dice pool, a read-the-best-die pool, a split-dice structure like the ones surveyed earlier. These produce different games altogether, and they're the furthest thing here from a variant.
Nearly every number in the engine assumes a single result compared to a single target, so a pool or split-dice system means rebuilding Defenses, difficulty, and contests from scratch. Worth doing only if the mechanism is the game you're trying to make, in which case you're using Frontiers' other subsystems as parts instead of adopting its resolution at all.
Change the verdict¶
Keep the spine but change what a roll means. Go pure binary by cutting the Gradient, for a stark, fast game. Or go the other way and make a mixed result the common outcome, a wide middle band of success-at-a-cost in the manner of the narrative traditions, so a roll that settles the matter outright becomes the exception. The second is the larger change, since it asks the table to author a cost on most rolls, and it shifts the whole game toward the story-forward end of the spectrum.
Whichever direction you take, resolution is the deepest thing to change, because it's the thing every other rule was written to sit on top of. Change it last, change it deliberately, and expect to revisit everything downstream when you do.