Basic Combat¶
| Author | Jayke Paver |
| Type | Additive module · official |
| Built for | Frontiers 1.0, any Ruleset |
Frontiers does not assume combat. A system built on the engine might turn on exploration, negotiation, survival, or intrigue and never roll a single attack. Nothing in the core rules requires structured violence.
This module is for the systems that want it.
It is one worked answer, not the answer. It adds no new resolution layer and changes no core rule, so you can adopt it as written, take the parts you want, or replace it entirely.
The rules here work on any of the three Rulesets unchanged. The gear at the end does not, and says so where it sits: those cards are a worked example on a twenty-point scale, and a system on the d100, or one that has cut ϟ Demand, will keep their shape and supply its own numbers.
Combat is an Encounter¶
Combat is not a separate mode. It is Encounter play with someone trying to hurt you.
Everything structural comes from your Ruleset already: Rounds and Turns, ✦ Action Points, ⇉ Movement, ➤ Initiative, and Reactions paid out of the ✦AP you did not spend. This module adds nothing to that and changes none of it.
An attack is an ✦ Action like any other. Unless something says otherwise, it costs 1 ✦AP.
Making an Attack¶
An attack is a Resolution roll against one of the target's Defenses. Your Ruleset already defines how that roll works; this module only says which Defense to aim at and what happens afterward.
1. Declare. Name the target, what you are attacking with, and how.
2. Find the Attribute. Whatever fits the approach. A heavy swing is ❖ Vigor, a placed shot ✩ Deft, a psychic intrusion ◉ Acuity or ◬ Resolve. The GM confirms.
3. Pick the Defense. Harm to the body goes against ⛊ Physical Defense. Harm to the mind goes against ⛉ Mental Defense. That is the whole distinction.
4. Resolve it, exactly as your Ruleset resolves anything against a Defense:
| Ruleset | How an attack resolves |
|---|---|
| d18 | Roll the Resolution Dice, add your Rank. Meet or beat the target's ⛊ or ⛉ Defense. |
| d20 | Roll the Resolution Die, add your Rank. Meet or beat the target's ⛊ or ⛉ Defense. |
| d100 | Take your Routine Target, subtract the target's ⛊ or ⛉ Defense, then roll at or under what is left. |
The two shapes look different and ask the same question: did you clear the defender. In the roll-over Rulesets the Defense is the bar you jump. In the d100 it comes off your Target before you roll, so a better-defended foe leaves you less room. Nothing else changes.
5. Read the Gradient, if the degree matters. On the d18 and d100 it is already in your hand; on the d20 it is the separate die.
6. Apply damage if you hit, or the Gradient's consequence if you did not.
Reading the Gradient in Combat¶
This is the one place the module has to know which Ruleset you are using, because each reads its Gradient differently. The idea is the same in all three: a Positive Gradient sharpens the result, a Negative one dulls it.
| Ruleset | Positive | Negative |
|---|---|---|
| d18 | 1d6 shows 5–6 |
1d6 shows 1–2 |
| d20 | Major only: 1d10 shows 10 |
Major only: 1d10 shows 1 |
| d100 | units die shows 0–1 | units die shows 8–9 |
And what they mean:
| On a hit | On a miss | |
|---|---|---|
| Positive | Critical Hit: double damage | Graze: half damage, no riders |
| Standard | Hit | Miss |
| Negative | Graze: half damage, no riders | Critical Miss |
A Graze deals half damage, rounded down, and triggers none of the attack's other effects. A Critical Hit doubles the damage dice total; bonuses that trigger because of a Critical Hit are not themselves doubled.
A Critical Miss has no fixed consequence here, because the right one depends on your game's tone. Pick one and hold to it across the system: the attacker provokes a free Reaction, drops what they are holding, or grants Favor on the target's next attack against them.
Critical Rates Differ by Ruleset¶
The three Rulesets are not close to each other here, and the gap is wide enough to mis-size a whole combat system. Read this before you tune anything.
Count criticals on hits, not on rolls¶
What matters for combat is not how often a Positive Gradient comes up, but how often it comes up on a hit. On the d20 and d100 those are the same number, because their Gradients are independent of the verdict: 10% and 20% respectively, at any difficulty.
On the d18 they are not the same number, because the weld is precisely what stops them
being the same. A high 1d6 pushes the sum toward success and reads as Positive, so
criticals concentrate in exactly the rolls that already landed. Across the full
72-outcome space:
| Anchor | Chance to hit | Criticals per hit |
|---|---|---|
| DT 8, Rank +0 | ~71% | ~41% |
| DT 10, Rank +0 | ~54% | ~44% |
| DT 12, Rank +0 | ~38% | ~48% |
| DT 12, Rank +3 | ~63% | ~42% |
| DT 14, Rank +3 | ~46% | ~45% |
So roughly two landed hits in five are criticals, and that figure never drops below ~41% anywhere in ordinary play. These are not edge cases; on the d18 the critical is close to a coin flip on every hit, and a combat system tuned as though it were rare will be wrong by a factor of four.
If you want criticals to be rare¶
Use the d18's edges only Gradient configuration, which brings it to ~22–26% per hit. That is a real reduction, though still twice the d20's rate.
The rate is not fixed by the Ruleset alone¶
Favor may be placed on either Resolution die, and the d18's 1d6 is read twice, so
Favor placed there moves the Gradient as well as the sum. At DT 12, Rank +0, Favor on
the 1d12 leaves criticals at ~45% of hits; Favor on the 1d6 takes them to ~66%.
Position hands out Favor for flanking, so a flanking attacker on the d18 is
effectively choosing their own critical rate.
Disfavor pushes the same way for the opposite reason: it strips out the low-1d6 hits,
so attacking into cover yields more criticals per landed hit, not fewer.
What a landed hit actually delivers¶
Counting criticals as double and Grazes as half, an average landed hit delivers about +5% over its printed damage on the d20, +10 to +15% on the d100, and +28 to +39% on the d18. That last figure is the one to build against; see Damage.
The d100 is given as a range rather than a single number because its units die is part of the roll, not a separate die. Low units digits are slightly over-represented among successes on a roll-under, so criticals run a little above 20% of hits at most Targets, reaching 20% exactly only where the Target closes a full band of ten.
Damage¶
Damage reduces the target's ✚ HP. Weapons and Abilities carry their own damage; this module only sets the structure.
Damage is the weapon's dice, and nothing else. No Attribute Rank is added by default. Your Rank already decided whether you hit; adding it again to damage compounds the same advantage twice. Adding it is a supported extension below, but it is a real change in lethality, not a small one.
When damage brings a target to 0 ✚ HP, they take one ⊗ Wound and are downed, exactly as the Ruleset describes. This module does not alter ⊗ Wounds, ⊖ Fatigue, death, or recovery.
For how hard a hit should land, use the Ruleset's own anchor: a competent character spending 1 ✦AP on a native ability should output roughly 10–15% of an even target's ✚ HP per landed hit, landing 50–75% of the time against that target. Both halves matter. Damage alone will not pace a fight, because how much of it arrives depends on how often it connects.
Build your weapon dice to sit in that band, with one correction applied first: the band describes damage before the Gradient, and the Gradient is not free. Criticals and Grazes together move what an average landed hit actually delivers, by roughly +5% on the d20, +10 to +15% on the d100, and +28 to +39% on the d18. Size your dice against the post-Gradient figure rather than the printed one (see Critical Rates Differ by Ruleset).
Attacking More Than Once¶
A character may attack as many times in a Turn as they can pay for. The limit is ✦AP, and the pressure is what they give up by spending it.
Because Reactions come out of the same pool, a character who empties it attacking has nothing left to defend with until their next Turn. That is the whole tension, and it needs no extra rule: swing three times and you are wide open.
If you want attacking repeatedly to bite harder than that, add the strain extension below.
Position¶
Where people stand should matter, and in Frontiers that is expressed as Favor and Disfavor rather than numbers. Circumstance is the engine's job, and it already has a tool for it.
| Situation | Effect |
|---|---|
| Partial cover | Disfavor on ranged attacks against the target |
| Full cover | The target cannot be hit by ranged attacks at all |
| Concealment (dark, fog, smoke) | Disfavor on attacks against the target |
| Flanking (two allies on opposite sides) | Favor on both attackers' rolls |
| Outside a weapon's range | Disfavor, or simply impossible |
Cover and concealment stack in the fiction but not in the maths: Favor and Disfavor cap at 3 either way, and cancel one for one, as the Ruleset defines.
Distance is measured in ⌗ Units. Weapons should state their reach:
| Band | Reach | Typical |
|---|---|---|
| Melee | 1 ⌗ | Blades, fists, clubs |
| Reach | 2 ⌗ | Polearms, whips, long spears |
| Short | 4 ⌗ | Thrown weapons, sidearms |
| Medium | 12 ⌗ | Bows, longarms |
| Long | 24 ⌗ | Sniper weapons, siege shots |
These bands are a starting point, not a standard. Change them freely; the only thing the engine cares about is that a weapon says how far it reaches.
Contests, Reactions, and Abilities¶
Three things combat inherits without modification.
Contests. Grappling, disarming, shoving, overpowering, a battle of wills: these are Contests, resolved exactly as the Ruleset describes, with both sides rolling and the higher result winning. A contested exchange is one ✦ Action however long it takes in the fiction.
Reactions. Paid from the ✦AP a character has not spent. This module defines no Reactions of its own; a system supplies them as Abilities. Parrying a blow, striking a foe who turns away, following someone who withdraws: all of these are Abilities written in the standard form, not special combat rules.
Abilities. They work in combat exactly as they work anywhere. ✦AP costs, ϟ Energy costs, Demand and Capacity, Overspend: all unchanged. An Ability that attacks simply says what it rolls against.
Defeat¶
A character leaves the fight when their ✚ HP reaches 0, when ⊖ Fatigue would pass its maximum, or when an effect incapacitates them. ⊗ Wounds past the maximum are death. All of that is the Ruleset's, unchanged.
The core engine provides no way to revive an ally mid-fight, because how forgiving a game is at that moment is one of its defining choices. This module supplies one, because a combat system needs an answer:
Touch a downed ally. They return to consciousness at 1 ✚ HP. Their ⊗ Wounds are unchanged, so they are still injured and still easy to drop again.
That is intentionally thin. It costs two thirds of a Turn, brings someone back at their most fragile, and does nothing about the injury itself. A system that wants combat to be more forgiving should give characters real healing Abilities; a system that wants it lethal can drop this rule entirely and let the downed stay down until the fight ends.
Weapons and Armor¶
Equipment in Frontiers carries its own Actions. There is no generic "attack" rule for a weapon to reference: the weapon is the attack, written as a card and available only while it is Equipped.
That means building weapons for this module is building Abilities. What follows is a sample of sixteen items across the common shapes, showing the pattern instead of defining a list. A system supplies its own.
Take them as a pattern first and a list second. Every card below carries a ϟ Demand and a Defense number, and both of those assume things a system is free not to assume: a system that cuts Demand and Capacity ignores that line entirely, and a system on the d100 needs the Defense numbers rewritten to its own scale.
These are tuned for mid-tier play
The damage below sits inside the engine's 10–15% band for a character around Level 5 — but only for a durable one. ✚ HP varies severalfold across builds at the same Level, and a single figure hides that:
| Level 5 build | ✚ HP | 1d6 raw |
After the d18 Gradient |
|---|---|---|---|
| ❖ 10 / ◬ 10 | 13 | 27% | 36% |
| ❖ 11 / ◬ 11 | 18 | 19% | 26% |
| ❖ 12 / ◬ 12 | 23 | 15% | 20% |
| ❖ 13 / ◬ 13 | 28 | 13% | 17% |
These cards were built against the bottom row. Against a character who put
nothing into ❖ Vigor or ◬ Resolve, the same 1d6 is two to three times the
band. That is the Ruleset's warning about the even target being a median made
concrete: treat spike damage as something the party's most fragile member feels
first.
The extremes move further still. At Level 1 a pool runs from 5 to 9, and a
1d6 takes half of it or more. Early combat with these numbers is genuinely
lethal. At Level 10 a pool runs from 23 to 63, and at the top of that range
the same 1d6 barely registers.
Weapon dice do not scale on their own. If you want a consistent feel across a campaign, either grow the dice as characters level, or lean on higher-Demand weapons doing the growing for you.
Weapons¶
Resolution roll against a target's ⛊ Physical Defense within 1 ⌗ Unit. On a success, deal 1d6 damage.
You may draw or stow this weapon as part of the same ✦ Action.
Resolution roll against a target's ⛊ Physical Defense within 1 ⌗ Unit. On a success, deal 1d8 damage.
Resolution roll against the ⛊ Physical Defense of every adjacent target. On a success, deal 1d8 damage to each.
On a Negative Gradient, you are left off balance and cannot take Reactions until the start of your next Turn.
Resolution roll against a target's ⛊ Physical Defense within 2 ⌗ Units. On a success, deal 1d6 damage.
Resolution roll against a target within 2 ⌗ Units. On a success, they cannot move closer to you until the end of their next Turn.
Resolution roll against a target's ⛊ Physical Defense within 4 ⌗ Units. On a success, deal 1d6 damage.
No Disfavor when a target is adjacent to you.
Resolution roll against a target's ⛊ Physical Defense within 12 ⌗ Units. On a success, deal 1d6 damage.
As Loose, but you have Favor on the roll and deal 1d8 damage instead.
Resolution roll against a target's ⛊ Physical Defense within 12 ⌗ Units. On a success, deal 1d8 damage.
Disfavor if a target is within 1 ⌗ Unit of you.
Resolution roll against a target's ⛊ Physical Defense within 24 ⌗ Units. On a success, deal 1d8 damage.
Disfavor if you moved this Turn, or if a target is within 2 ⌗ Units of you.
Resolution roll against a target's ⛊ Physical Defense within 4 ⌗ Units. On a success, deal 1d6 damage.
The weapon lands at the target's feet. Recovering it is an ✧ Interact once you reach it.
Armor¶
Armor is the one place this module hands out a flat number, not Favor. It earns the exception by being a standing property of the character, not a circumstance of the moment: it is true every round, it never needs sizing at the table, and it sits on the sheet where a Defense already lives.
These Defense numbers are written on a twenty-point scale
The damage on the weapon cards transfers between Rulesets cleanly, because it is measured against ✚ HP and ✚ HP is identical in all three. The armor numbers do not, because a Defense means something different in each:
- On the d18, Defense is a bar on a curve near 10. +2 is worth roughly 15 percentage points of hit chance.
- On the d20, Defense is a bar on a flat die. +2 is exactly 10 points.
- On the d100, Defense is subtracted from the attacker's percentile Target. +2 is 2 points, roughly an eighth of what it is worth above.
Use these cards as written on the d18 or d20. On the d100, keep the pattern and rewrite the numbers: a Defense worth having there sits in the 6–12 range, rising to about 30 for something exceptional.
While Equipped, gain +1 to ⛊ Physical Defense.
Light enough to pass unnoticed. No penalty to anything.
While Equipped, gain +2 to ⛊ Physical Defense and Disfavor on Body rolls that depend on stealth.
Donning or removing it is an ✽ Activity.
While Equipped, gain +3 to ⛊ Physical Defense and Disfavor on Body rolls that depend on stealth or agility.
Your ⇉ Movement is reduced by 1 ⌗ Unit, never below 1. Donning or removing it is an ✽ Activity.
While Equipped, gain +1 to ⛊ Physical Defense. Occupies a hand.
Until the start of your next Turn, attackers have Disfavor on rolls against your ⛊ Physical Defense.
While Equipped, gain +2 to ⛊ Physical Defense. Occupies a hand, and your ⇉ Movement is reduced by 1 ⌗ Unit.
Plant the shield. Until you move, you and one adjacent ally count as being in partial cover.
While Equipped, gain +2 to ⛉ Mental Defense.
Costs no Slots. Its Demand is what limits who can carry one.
While Equipped, gain +1 to ⛊ Physical Defense and ignore Disfavor from difficult footing.
Built for work, not war, and unremarkable to look at.
While Equipped, gain +3 to ⛊ Physical Defense, +2 ⌗ Units of ⇉ Movement, and Favor on Body rolls that depend on raw strength.
Far beyond a starting character. A Capacity 1 wearer cannot bring it online at all.
Note what the cards do and do not carry. They state their damage, their reach, their Slots, and their Demand. They do not name an Attribute, because the approach decides that at the table, and they do not require a Skill, because a weapon almost never should.
Five of them are out of reach at first. A starting character has Capacity 1, so everything at ϟ Demand 1 is native to them and free. The Marksman's Rifle, Heavy Plate, Tower Shield, and Warding Charm sit at Demand 2, and the Powered Frame at Demand 5, so a starting character carrying one operates diminished until they grow into it. That is what Demand is for: showing a player what advancement looks like, in an object they can already hold.
Tone Is Yours¶
This module sets structure. How lethal your game feels comes from decisions it does not make for you:
- How large ✚ HP pools are, and how fast they grow.
- How much damage a weapon deals against that pool.
- How often criticals land, which your Ruleset's Gradient decides.
- Whether healing exists at all, and how much of a Turn it costs.
- How readily ϟ Energy lets a character reach past themselves.
A heroic game lets characters trade blows for several Rounds. A horror game makes one landed hit a crisis. Neither needs a different combat system, only different numbers poured into this one.
Add-Ons¶
None of the following is part of the module, and none of it is required to run combat. Each entry is a lever that changes how a fight feels, not how it works: how lethal it is, how much positioning matters, how much a single roll can swing. Take them one at a time and play between each, because two of them stacked will move your game further than either did alone.
Each is listed with what it costs, not only what it buys.
Attribute damage¶
Add the governing Attribute's Rank to damage.
Characters hit noticeably harder as they advance, and growth translates directly into combat weight. It also compounds the same Rank twice, once on the attack and again on the damage, so lethality climbs faster than it looks like it should. Defenses and ✚ HP need to scale with it.
Armor as reduction¶
Armor subtracts a flat amount from incoming damage, on top of, or instead of, its Defense bonus.
Armor starts feeling like protection and not evasion: small hits stop mattering entirely, large ones still land. It makes low-damage attacks worthless against armored foes, which is either exactly what you want or a trap for characters built around many small strikes.
Numeric position bonuses¶
Replace the Favor and Disfavor in Position with flat numbers, typically ±2.
More granular, more tunable, and more familiar to players coming from other games. The cost is the one the engine warns about: situational numbers have to be sized, they stack without a cap, and a table ends up arguing about whether this particular wall is worth 2 or 4.
Strain from repeated attacks¶
A character's third and later attacks in a single Turn cost 1 ⊖ Fatigue on a miss.
This restores a hard brake on attacking repeatedly, beyond the soft one of having no ✦AP left to react with. It suits grittier games, and it uses the engine's own logic: ⊗ Wounds come from what is done to you, ⊖ Fatigue from what you do to yourself.
Aim¶
Spend 1 ✦AP before an attack to gain Favor on it.
A commit-to-one-strike option for characters who would rather land one good hit than three uncertain ones. Cheap to add, and it gives ranged characters something to do with a spare point.
Lethal criticals¶
A Critical Hit inflicts 1 ⊗ Wound as well as its double damage, regardless of remaining ✚ HP.
Every critical now carries lasting consequence, and characters accumulate injuries across a fight rather than only at its end. Check its critical rate against your Ruleset before adopting, because the rates are far apart. On the d18's default Gradient this inflicts a ⊗ Wound on about four landed hits in ten, against a track that maxes at five. On the d20 it is one in ten. The same add-on produces two very different games.
Weapon-specific critical misses¶
Instead of one consequence, a Critical Miss does something particular to the weapon: a heavy blade is dropped, a bow's string snaps, a firearm jams, an implement discharges wildly.
Weapon choice gains identity beyond its damage die. It costs a line of text on every weapon, and a table that has to remember them.
Using This Module¶
- Set your damage dice against the 10–15% anchor for your Ruleset's ✚ HP scale.
- Write your weapons as Ability cards. The templates above show the shape.
- Choose a Critical Miss consequence and use the same one everywhere.
- Decide on Stabilize. Keep it, replace it with real healing Abilities, or cut it and let the downed stay down.
- Pick your add-ons. Each is a change of feel, not a bolt-on.
- Play it. Combat tone emerges from the interaction of ✚ HP, damage, critical rate, and recovery. Numbers on paper will not tell you how it feels.
Attribution for systems using this module. Basic Combat is an official module, so it does not need a credit line of its own. Name it alongside the engine:
Powered by the Frontiers Engine 1.0 with the Basic Combat module. © 2026 Jayke Paver · frontiersengine.dev · Open RPG Creative (ORC) License
The full requirements are in the License.