---
# System prepended metadata

title: Design Documentation - Flow of Play - Beta 2026-2
tags: [Beta 2026-2]

---

# Flow of Play
### Design Documentation

This is one piece of the **Design Documentation** for Frontiers Beta 2026-2. For a guide to the full Design Documentation set and how to read it, see [Designing With Frontiers](https://hackmd.io/@frontiers-engine/Designing_2026-2).

If you want the ruleset only, skip to ***Default Rules*** using the left-side menu, or read the [Frontiers Overview](https://hackmd.io/@frontiers-engine/Overview_2026-2) for the condensed version. If you want the reasoning behind those rules, read top to bottom.

 
 

---
 
 

# Part One: The Structure of Play in TTRPGs

This section is the teaching part of the document. It exists to explain how tabletop games organize time, action, and consequence. None of this is Frontiers-specific. If you already understand action economies and turn structures thoroughly, you can skip ahead to Part Two.

 

## What "Flow of Play" Means

Every tabletop game has to organize three things: when things happen, who decides what happens next, and what each thing costs.

Some games handle this implicitly. Conversational systems like [Fiasco](https://bullypulpitgames.com/games/fiasco/) trust the players to manage pacing through scene framing alone. Some games handle it rigorously. Tactical games like Pathfinder 2nd Edition track every action point and movement square.

Most tabletop games sit somewhere in between. The framework that organizes all of this is the game's **Flow of Play**.

Flow of Play is invisible when it works and infuriating when it doesn't. A good Flow of Play makes a fight feel decisive, a chase feel breathless, a quiet conversation feel patient. A bad one makes every scene feel like a turn-tracker spreadsheet.

Designers underestimate this system constantly. It is the second-most-played-with subsystem in any TTRPG (after the [resolution system](https://hackmd.io/@frontiers-engine/DD_Resolution_2026-2)), and it shapes how every other mechanic feels at the table.
 

## The Two Tempos

Most games oscillate between two modes of time:

- **Unstructured time.** Conversation, exploration, planning, downtime. No turn order. Time advances fluidly. Some hours pass in a sentence; some sentences take an hour.
- **Structured time.** Combat, chases, time pressure. Turn order matters. Actions are bounded. Every second of in-fiction time is mechanically tracked.

The terminology varies wildly across games:

| System | Unstructured | Structured |
|---|---|---|
| Frontiers | Free Play | Encounter Play |
| [Blades in the Dark](http://www.bladesinthedark.com/) | Free Play | Score |
| [Powered by the Apocalypse](https://apocalypse-world.com/) | Conversation | Move-driven beats |
| [Mothership](https://www.tuesdayknightgames.com/pages/mothership-rpg) | Standard Play | Violent Encounters |
| Traditional d20 systems | Exploration | Combat |

The pattern is universal because the *needs* are universal. Players need a low-friction mode for talking, planning, and exploring, where the rules get out of the way. They also need a high-pressure mode where positioning and timing are decisive, and the rules become load-bearing.

The interesting question is not whether to have two tempos. It is **how cleanly the boundary between them is drawn, and who gets to draw it**. Some games make the shift abrupt and rules-driven. Others let it bleed naturally from the fiction. Both are valid. Designers pick based on the feel they want.
 

## The Four Pressure Levers

Every action economy is, underneath, managing four levers. Most designers tune them without naming them. Once named, they become tools.

These four levers describe the foundational tradeoffs every Flow of Play system has to make. Like the Four Axes of Resolution, they show up consistently because they describe the structural constraints all games face.
 

### 1. Time

How much can a character do in one moment?

The answer ranges widely. [Mothership](https://www.tuesdayknightgames.com/pages/mothership-rpg) gives characters one or two actions per round, kept lean to match its survival horror tone. Pathfinder 2nd Edition gives three actions per round, used for granular tactical choice. [Mörk Borg](https://morkborg.com/) abstracts time so loosely that "a round" means roughly "as much as fits the moment."

**Why this lever matters.** Fewer actions per turn means each one matters more. The cost is reduced tactical breadth. More actions per turn means richer combinations of movement, attack, and effect. The cost is longer turns and more decision paralysis.

A designer's pick on this lever directly determines turn duration at the table.
 

### 2. Position

Does where a character stands matter?

Some games care a lot. Tactical systems use grids, miniatures, range increments, and area templates. Other games abstract position into zones (Engaged / Near / Far). Still others ignore position entirely and resolve everything narratively.

**Why this lever matters.** Strict positioning rewards spatial reasoning, terrain choices, and prepared tactics. The cost is that combat slows to map upkeep. Loose positioning frees the table to focus on character and consequence. The cost is that flanking, cover, and positioning-based abilities lose mechanical teeth.

A system's pick here reveals whether it wants combat to feel like *chess* or like *cinema*.
 

### 3. Resource

What are the character's resources?

Almost every game tracks something. Hit points. Spell slots. Action points. Stress. Stamina. Mana. Ammunition. Sanity. The choice is what to track, how fast it depletes, and how easily it refills.

**Why this lever matters.** Tight resource tracking creates tension. Players have to spend carefully and feel real consequence when something runs out. The cost is bookkeeping, and a sense that the game cares more about the spreadsheet than the story. Loose resource tracking removes friction. Players act freely without checking pools. The cost is that risk becomes abstract, and clever resource management stops being a play style.

A designer's pick determines whether the game feels like *survival* or like *adventure*.
 

### 4. Initiative

Who acts when?

Most games answer with some form of turn order. The variations matter:

- Fixed initiative (rolled once per encounter, used the whole fight)
- Re-rolled initiative (every round)
- Side-based initiative (one whole side, then the other)
- Popcorn initiative (the active player picks who goes next)
- Simultaneous declaration (everyone declares, then resolves)

**Why this lever matters.** Initiative shapes who feels powerful at any given moment. Going first lets a character control the encounter's opening. Going later lets them react to what others have already done. A system's initiative method also determines pacing: faster systems use simpler initiative, more tactical systems use richer initiative.

The pick reveals whether the system values *initiative as a stat to optimize* or *initiative as a turn-order convenience*.
 

## The Point

There is no correct setting for any of these levers. Each combination produces a different feel of play.

A designer's most consequential decision after the resolution system is how the action economy works. It determines how every encounter feels, how long combat takes, how often players feel powerful versus reactive, and how much bookkeeping the table tolerates.

Get the contract wrong and the game feels either fiddly or shapeless. Get it right and the players stop noticing the rules entirely. The fiction takes over.

 
 

---
 
 

# Part Two: Frontiers' Flow of Play

This section covers the specific choices Frontiers made and the reasoning behind them. The earlier section explained the field. This section explains the answer.

 

## The Design Question

When designing Frontiers, the goal was a Flow of Play that could shift cleanly between casual exploration and high-pressure conflict without making them feel like two different games. Most existing systems treat combat as a separate subsystem with its own rules; Frontiers wanted one consistent grammar that intensifies under pressure rather than transforming into something else.

That goal narrowed the design space immediately:

| Goal | Reasoning | Constraint |
|---|---|---|
| Two modes, one engine | A new player should never feel like they're learning a second game when combat starts | Argues for shared mechanics across modes |
| Action economy that scales | Tactical players want depth, casual players want speed | Argues against fixed complexity |
| Resource pressure that creates choice, not bookkeeping | Players should feel decisions, not tracking | Argues for few resource pools, each meaningful |
| Initiative that supports build identity | Some characters should feel fast, some should feel reactive | Argues against pure randomness |
| Lethality that has weight without being arbitrary | Death should mean something, but not from a single bad roll | Argues for layered damage tracks |

 

### The Tradeoffs Considered

Frontiers studied [Mothership](https://www.tuesdayknightgames.com/pages/mothership-rpg)'s lean combat economy, [Blades in the Dark](http://www.bladesinthedark.com/)'s zone-based positioning, [Powered by the Apocalypse](https://apocalypse-world.com/)'s no-turn-order conversation flow, and [Pathfinder 2nd Edition's](https://paizo.com/pathfinder) three-action structure. Each was studied for what it does well and where it leaves gaps.

**Lean economies** (Mothership, Mörk Borg). Fast turns, brutal consequences. But limited tactical breadth, and the same encounter repeats with little variation.

**Rich economies** (Pathfinder 2e, D&D 4e). Deep tactical play. But long turns and a steep learning curve.

**No-economy systems** (PbtA-style). Maximum narrative flexibility. But combat feels like a regular conversation, which some players want and many do not.

**Hybrid economies** (Blades, Forged in the Dark). Strong narrative grounding with lightweight tactical structure. Closest in philosophy to where Frontiers wanted to land.

The target was *enough structure to make positioning and resource decisions meaningful, without enough to make every turn feel like a math problem*.

The answer Frontiers landed on: **two modes, four resources, one consistent grammar**.

 
 
 

## Frontiers' Answer — Two Modes, Shared Grammar

Frontiers organizes time into two modes:

| Mode | Used For | Key Feature |
|---|---|---|
| **Free Play** | Exploration, conversation, downtime, planning | Time is fluid. No turn order. Activities advance the fiction. |
| **Encounter Play** | Combat, chases, time-critical scenes | Time is structured. Initiative determines order. Actions cost AP. |

The shift between modes is GM-called. When timing, position, and resource pressure start to matter, the game enters Encounter Play. When the pressure releases, it returns to Free Play.

 

### What This Buys

The choice to keep one engine across both modes was load-bearing for the engine, and the upsides justified it:

- **One game to learn.** A new player who learns how to attempt a Resolution Roll already knows how to attempt one in combat. The mode changes; the grammar does not.
- **Easy mode-switching.** A scene that escalates from conversation to violence does not require rule-rebooting. The same dice, the same modifiers, the same Skills apply throughout.
- **Designers can intensify or relax.** Systems built on Frontiers can dial up or down the structure of Encounter Play without rewriting the engine. A combat-light system can use almost the same rules as a tactical-heavy one.

 

### What This Costs (And Why That's Fine)

**The boundary between modes is GM-called, not rules-defined.** This is intentional. A rules-defined boundary would mean a checklist for "when does combat start," which would be brittle and feel artificial. Frontiers trusts the GM to make the call, the same way they call for rolls. The cost is occasional ambiguity. The benefit is that the fiction always determines the moment, not a flowchart.

**Activities cannot always be compressed into Actions.** Some efforts (rituals, crafting, research, deep negotiation) take time that no single Encounter Turn can contain. Frontiers handles this by separating Activities (Free Play efforts that may take minutes or hours) from Actions (Encounter efforts bounded by AP). They are the same *kind* of effort under different time pressure. They are not interchangeable.

 

## The Action Economy Choices

Encounter Play uses four pools: ✦Action Points, ⇉Movement Points, ⚡︎Energy, and ➤Initiative. Each one was tuned deliberately.

 

### Why 3 Action Points Per Turn

Frontiers gives each character **3 ✦AP per Turn**. This is the central pacing choice of the action economy.

- **2 AP** would force harder choices but reduce tactical breadth. A character could attack and use an ability, but rarely attack twice or use a special ability and still have options.
- **4 AP or more** would create longer turns and decision paralysis. Pathfinder 2e's three-action economy already approaches this ceiling for most tables.
- **3 AP** sits in the sweet spot: enough room for an attack, a reposition, and a tactical option, without so much room that turns sprawl.

3 AP also creates a clean shape for Ability design. A 1-AP ability is quick. A 2-AP ability is committed. A 3-AP ability is a turn-defining choice. Designers building Abilities have three meaningful tiers to work with.

 

### Movement Separated From Action Points

In some systems (older D&D, Pathfinder 2e), movement competes with attacks for the same action pool. Frontiers separates them: ⇉MP is its own resource, refreshed each Turn, used independently of ✦AP.

The reason is identity. In a unified-pool system, a slow character is just an inefficient character. They spend more of their pool on movement and have less left for attacks. In a separated-pool system, a slow character is a *distinctly different* character. They have less mobility, but their tactical pool is unaffected. Builds that emphasize positioning and builds that emphasize action density both feel valid.

 

### Free Actions: Once Per Round Per Ability

A ✧Free Action ability may be used **once per Round, per ability**. Multiple different Free Action abilities may be used in the same Round.

This means a character with two Free Action abilities can use both in a single Round, but cannot spam either of them. The intent is to reward broad ability builds without enabling a single overpowered ability to dominate every Round.

This rule is more permissive than systems that cap Free Actions globally (one per Round, period) and more restrictive than systems that allow unlimited Free Actions (which inevitably break under optimization). The middle ground is intentional.

 

### Reactions Share Your Action Pool

This is the most unusual choice in Frontiers' action economy, and worth a closer look.

In most TTRPGs, Reactions exist as a separate pool. A character has "one Reaction per Round" that resets at the start of their Turn. The Reaction is mechanically free, costing nothing the character was already going to do.

Frontiers does it differently. **Reactions cost ✦AP from the same pool a character uses on their own Turn.** Unspent ✦AP persists through the rest of the Round after a character's Turn ends, specifically so it can fund Reactions. At the start of a character's next Turn, ✦AP refreshes to maximum, overwriting anything left over.

This creates a tactical loop that does not exist in most systems. Every Turn, a player chooses between *spending offensively* and *saving for Reactions*. Dumping all 3 ✦AP into attacks leaves a character reactively helpless until their next Turn. Holding 1 ✦AP back means less pressure applied now, but the ability to interrupt, counter, or react to something that happens between Turns.

Characters who act later in a Round get an interesting side-benefit from this structure. They have fewer "others' Turns" between their refresh and their next action, which means less opportunity to burn their ✦AP on Reactions before it refreshes anyway. Characters who act early have the opposite situation. Their ✦AP has more exposure to Reaction triggers across the rest of the Round. Both positions have tactical weight.

In Frontiers, using a Reaction is an active sacrifice. A character who interrupts an enemy attack pays for it on their next Turn. This makes reactive builds genuinely tactical. A player who wants to be a counterpuncher must accept that their offensive turns will be lighter, and a player who wants maximum offense must let some Reaction triggers go unanswered.

This rule is one of the engine's defining tactical choices. It rewards reactive build identity without requiring a separate resource pool to manage.

 

## The Initiative Choice

Frontiers calls turn order **Initiative**. Each character has an Initiative Value (IV) from 0 to 10, established at the start of an Encounter. **Higher Initiative acts first.**

A character may adjust their IV at the start of an Encounter by adding or subtracting up to their ⚝Finesse Modifier. This makes Finesse-heavy characters faster *or* lets them choose to act later, depending on tactical needs.

Three things to note:

**Higher acts first.** This matches universal player intuition. Every dice game and most video games use the same convention. Frontiers does not invert it.

**The 0–10 range is firm by default.** Effects can push beyond temporarily, but normal Initiative stays within the range. This keeps initiative comparisons fast and intuitive.

**Adjustment is bidirectional.** A Finesse +3 character can shift their IV up to 3 in either direction. This lets fast characters act first by default but also lets them choose to wait, which is useful for Archetypes built around reactive play, ambushes, or tactical timing.

Initiative is not a stat to optimize relentlessly. It is a tactical knob. Most characters will set it once and forget it; some builds will manipulate it actively.

 

## The Pressure Resources

Frontiers tracks four pressure resources during play. Three of them (Energy, Wounds, Fatigue) carry across Encounters. One of them (Action Points) refreshes every Turn.

 

### Energy as Exertion Currency

⚡︎Energy represents stamina, focus, and the will to push beyond routine. It is spent when a character uses Abilities or Equipment above their effective Level.

Energy is unusual among TTRPG resources because it is not consumed by *every* meaningful action. A character can fight a normal Encounter and spend zero Energy. Energy is reserved for moments when the character is *exceeding their baseline*.

This makes Energy feel like a currency for special effort, not for normal play. It rewards tactical timing (when to push, when to conserve) without making every Turn feel like a budget exercise.

 

### Wounds and Fatigue: Two Damage Tracks

Frontiers uses two parallel damage tracks: ⊗Wounds (physical) and ⊖Fatigue (mental).

This is a deliberate departure from single-track systems where everything that hurts the character pulls from one HP pool. The two-track model is shared with games like [Mothership](https://www.tuesdayknightgames.com/pages/mothership-rpg) (Wounds and Stress) and [Burning Wheel](https://www.burningwheel.com/) (separate physical and emotional hit tracks).

**Why two tracks instead of one.** A unified pool makes "you are stabbed" and "you are terrified" feel like the same kind of harm. They are not. The two-track model lets physical and mental pressure escalate independently, and lets character builds care about resilience to one or the other.

This also gives the engine clean attack vectors. A combat encounter pressures Wounds. A horror encounter pressures Fatigue. A long political negotiation pressures Fatigue. A hard chase pressures both. Designers building scenarios have two distinct levers to pull.

 

### Overspend as Controlled Bleed

When a character does not have enough Energy to pay a cost, they may **Overspend**: declare the effect anyway and immediately gain either 1 Wound or 1 Fatigue (player chooses).

This is Frontiers' answer to the classic problem of "what happens when a player needs to do something they cannot afford?"

The choice was deliberately not a roll. Earlier drafts had a coin-flip mechanic, but rolling for a 50/50 outcome the player will always optimize against added ceremony without producing meaningful tension. The clean version: Overspend always costs, and the player chooses *which* track to bleed.

This makes Overspend a real choice rather than a gamble. A character with high Maximum Wounds will tend to Overspend into Wounds. A character with high Maximum Fatigue will tend to Overspend into Fatigue. Build identity informs the call.

 
 

---
 
 

# Part Three: The Working Ruleset

Everything below this point is the actual mechanics. The earlier sections explained the theory. This section explains how it runs at the table.

 

## Modes of Play

Frontiers operates in two primary modes: **Free Play** and **Encounter Play**.

 

### Free Play

Free Play is the default state of the game.

- Time is fluid.
- No strict turn order exists.
- Characters primarily engage in ✻Activities.
- Rolls occur only when uncertainty meaningfully impacts the narrative.

There is no Action Point tracking during Free Play.

If a situation escalates such that timing precision, positioning, or resource pressure becomes critical, the game shifts into Encounter Play. The GM determines when this shift occurs.

 

### Encounter Play

Encounter Play introduces structured timing.

Encounter Play is used when:
- Order of actions matters.
- Positioning matters.
- Immediate consequences matter.
- Resource tracking matters.

During Encounter Play:
- Time is divided into Rounds.
- Participants act in Turns.
- Actions consume ✦AP.
- Movement consumes ⇉MP.
- ⚡︎Energy pressure becomes tactically significant.

✻Activities are unavailable during Encounter Play unless explicitly allowed by a rule.

 

### Transitioning Into Encounter Play

When the game shifts from Free Play to Encounter Play:

- All participants determine Initiative.
- A new Round begins immediately.
- No participant begins with expended ✦AP or ⇉MP.
- Ongoing Free Play actions resolve or are suspended at the GM's discretion.

If a participant was clearly initiating action before others could respond, the GM may allow them to act first in the first Round regardless of Initiative.

 
 

## Encounter Structure

Encounter Play operates in repeating cycles called **Rounds**.

Each Round consists of every participant taking one **Turn**, ordered by **➤Initiative**.

After all participants have taken a Turn, a new Round begins. There is no fixed limit to the number of Rounds in an Encounter.

The Encounter ends when:
- The conflict resolves.
- The pressure dissipates.
- The GM declares the structured timing no longer necessary.

 

### Rounds

A Round represents approximately 10 seconds of in-world time.

All participants share the same Round. Effects that last "until the end of the Round" expire after all participants have completed their Turns. Effects that last "until the start of your next Turn" expire immediately before that participant begins acting again.

 

### Turns

A Turn is the window in which a participant may:
- Spend ✦AP
- Spend ⇉MP
- Use ✧Free Actions
- Trigger effects that specify "during your Turn"

At the start of a participant's Turn:
- ✦AP refreshes to maximum.
- ⇉MP refreshes to maximum.
- Ongoing effects that expire "at the start of your Turn" resolve.

At the end of a participant's Turn:
- Unspent ⇉MP is lost.
- Unspent ✦AP **persists** until your next Turn for use on Reactions.
- Effects that expire "at the end of your Turn" resolve.

A participant cannot take actions outside their Turn unless a rule explicitly grants a Reaction or exception.

 
 

## Initiative

Each character has an **Initiative Value (IV)** from 0 to 10. **Higher Initiative acts first.**

 

### Establishing Initiative

At the start of an Encounter:

1. Each participant uses their base Initiative Value (provided by Archetype).
2. A participant may adjust their IV by adding or subtracting up to their ⚝Finesse Modifier.
3. The final IV is locked for the duration of the Encounter unless altered by effects.

Participants then act in descending order of IV (highest first).

 

### Ties

If two or more participants share the same IV:
- The participant with higher ⚝Finesse Score acts first.
- If still tied, the GM decides.

That order remains consistent across Rounds unless circumstances change.

 

### Mid-Encounter Changes

Some Abilities or effects may modify IV during an Encounter.

If Initiative changes mid-Encounter:
- The new IV takes effect at the start of the next Round unless the rule states otherwise.
- Initiative changes do not retroactively reorder Turns already taken.

Effects may temporarily push IV beyond the 0–10 range. This is permitted within the engine.

 
 

## Action Timing Priority

When multiple effects trigger simultaneously:

1. Effects triggered by the active participant resolve first.
2. Effects triggered by other participants resolve in Initiative order (highest first).
3. If ambiguity remains, the GM determines resolution order.

Reaction chains resolve in reverse chronological order: the most recently declared Reaction resolves first.

Unless explicitly stated, triggered effects do not interrupt the resolution of an action. They resolve immediately after the triggering event completes.

 
 

## ✦ Actions

An ✦Action is a discrete, mechanically significant effort performed during Encounter Play.

Unless stated otherwise, all ✦Actions cost **1 ✦AP**.

Actions may include:
- Attacking
- Activating an Ability
- Interacting with the environment
- Utilizing equipment
- Improvised efforts adjudicated by the GM

If a rule does not specify an Action cost, it defaults to **1 ✦AP**.

 

### Declaring and Resolving an ✦Action

To perform an ✦Action:

1. Declare the intended Action.
2. Spend the required ✦AP.
3. Resolve the Action fully.
4. Apply any resulting effects.

An ✦Action must be fully resolved before another ✦Action is declared, unless a rule explicitly allows interruption.

A participant may not declare an ✦Action if they do not have sufficient ✦AP available.

 

### Multiple ✦AP Costs

Some Abilities or effects cost more than 1 ✦AP.

If an Ability requires:
- 2 ✦AP → both must be available at declaration.
- 3 ✦AP → all three must be available at declaration.

✦AP costs must be paid in full before resolution begins. Partial activation is not permitted unless explicitly stated.

 

### ✦ Action Points (AP)

During Encounter Play, each participant begins their Turn with **3 ✦AP**, unless modified by a rule.

✦AP may be spent:
- During your Turn for ✦Actions.
- During the Round for Reactions.

At the start of your Turn:
- ✦AP refreshes to maximum.

✦AP does not carry over between Turns.

 
 

## ✧ Free Actions

A ✧Free Action represents a minor effort that does not meaningfully tax time or focus.

If an Ability costs a ✧Free Action:
- It may be used **once per Round per ability**.
- It does not cost ✦AP.
- It may only be used during the participant's Turn unless explicitly stated otherwise.

A participant may use multiple **different** ✧Free Action abilities in the same Round. They cannot use the **same** ✧Free Action ability twice in a Round (unless a rule specifically allows it).

Free Actions must still be declared and resolved clearly.

 
 

## Reactions

Reactions are effects triggered outside a participant's Turn.

- Reactions cost ✦AP from the participant's **current pool**.
- A participant's ✦AP does not expire at the end of their Turn. It persists through the rest of the Round, available for Reactions, until their next Turn refreshes it.
- If a participant has 0 ✦AP when a Reaction trigger fires, they cannot use the Reaction.
- A participant cannot accumulate ✦AP across Turns. ✦AP refreshes to maximum at the start of each Turn, overwriting any leftover.
- Reactions resolve immediately after their triggering condition unless the rule states they interrupt.

Because Reactions draw from the same ✦AP pool a participant uses on their Turn, every Turn involves a tactical choice about how much ✦AP to hold back for reactive use.

A participant cannot use Reactions while incapacitated.

 
 

## ⇉ Movement

Movement represents physical repositioning during Encounter Play.

Movement is tracked using **⇉Movement Points (MP)**.

Movement does not normally cost ✦AP unless a rule explicitly states otherwise.

 

### ⇉ Movement Points (MP)

During Encounter Play:
- Each participant begins their Turn with **⇉MP equal to 3 + ⚝Finesse Modifier**, unless modified by a rule.
- ⇉MP refreshes to maximum at the start of the participant's Turn.
- Unspent ⇉MP is lost at the end of the participant's Turn.

1 ⇉MP = 1 ⌗Unit moved.

A participant may divide movement before, between, or after ✦Actions during their Turn. Movement does not need to be declared all at once.

 

### ⌗ Units

Distance in Frontiers is measured in **⌗Units**.

- 1 ⌗Unit = 5 feet (1.5 meters)
- 1 ⌗Unit = 1 square or hex on a tactical map

⌗Units apply to:
- Movement
- Ranges
- Areas of effect
- Positioning requirements

If playing without a grid, ⌗Units represent relative spatial positioning at the GM's discretion.

 

### Splitting Movement

Movement may be split across a Turn.

Example:
- Move 1 ⌗Unit
- Perform an ✦Action
- Move 2 ⌗Units

All movement must occur during the participant's Turn unless a rule explicitly allows movement outside it.

 

### Forced Movement

If a participant is moved by an external effect:
- Forced movement does not cost ⇉MP.
- Forced movement does not trigger additional movement costs.
- Forced movement occurs immediately when the effect resolves.

If forced movement would place a participant in an invalid or obstructed space, the GM determines the nearest valid position.

 

### Impaired or Reduced Movement

If an effect reduces movement:
- The reduction applies to the participant's total available ⇉MP for that Turn.
- Movement cannot be reduced below 0 unless a rule explicitly immobilizes the participant.

If immobilized:
- The participant cannot spend ⇉MP.
- They may still perform ✦Actions unless otherwise restricted.

 
 

## ⚡︎ Energy

⚡︎Energy represents stamina, exertion, and the capacity to push beyond routine effort.

⚡︎Energy applies in both Free Play and Encounter Play.

Energy is most commonly spent to activate Abilities or use Equipment above the user's effective Level.

 

### Spending ⚡︎Energy

When a character activates an Ability or effect that requires ⚡︎Energy:
- Determine the required Energy cost.
- Subtract that amount from the character's current ⚡︎Energy.
- If the character does not have sufficient ⚡︎Energy, they may Overspend.

Energy is spent immediately upon declaration of the Ability or effect. If an Ability fails or is interrupted after Energy is spent, the Energy cost is not refunded unless a rule explicitly states otherwise.

 

### Overspending ⚡︎Energy

If a character does not have sufficient ⚡︎Energy to pay a required cost, they may **Overspend**.

When Overspending:
- The Ability or effect is declared normally.
- The character immediately gains either **1 ⊗Wound or 1 ⊖Fatigue** (player chooses).
- ⚡︎Energy may drop below 0, up to the system's defined negative limit.

If the negative limit would be exceeded, the action cannot be taken.

Each instance of Overspend triggers its own Wound/Fatigue choice.

 

### Negative ⚡︎Energy Limits

A character may Overspend into Negative ⚡︎Energy up to:
- Half of their positive maximum ⚡︎Energy (rounded down).

Example: a character with 9 maximum ⚡︎Energy may go as low as -4.

If spending Energy would push them beyond this limit, the activation fails.

Negative ⚡︎Energy is tracked normally and recovers as standard Energy.

 

### Recovery of ⚡︎Energy

⚡︎Energy is regained during ⏾Downtime at a rate of **1 ⚡︎Energy per hour**.

Negative ⚡︎Energy recovers at the same rate as positive Energy.

Energy cannot exceed its maximum unless a rule explicitly allows it.

 
 

## ⊗ Wounds

⊗Wounds represent significant physical injury beyond momentary loss of ✚HP.

 

### Gaining a ⊗Wound

A character gains a ⊗Wound when:
- They are reduced to 0 ✚HP.
- A rule explicitly states a Wound is inflicted.
- They Overspend ⚡︎Energy and choose Wound as the cost.

When reduced to 0 ✚HP:
- The character gains 1 ⊗Wound.
- The character falls **Unconscious**.
- The character falls prone.
- The character cannot take ✦Actions, ✻Activities, spend ⇉MP, or use Reactions.

They remain Unconscious until they regain at least 1 ✚HP.

If the Encounter concludes and an ally can reach them, they automatically reawaken with 1 ✚HP.

 

### Maximum ⊗Wounds

Maximum ⊗Wounds = 1 + ❖Vigor Modifier.

If a character at 0 ✚HP would gain a ⊗Wound that exceeds their maximum: **the character dies.**

Death in Frontiers is a hard threshold. There are no death saves. Exceeding maximum Wounds is the death condition.

 

### Effects of ⊗Wounds

Each ⊗Wound imposes a cumulative penalty:
- -2 to ⛊Physical Defense
- -2 to ⛉Mental Defense

These penalties stack.

Wounds do not reduce Attribute Scores directly unless a rule states otherwise.

 
 

## ⊖ Fatigue

⊖Fatigue represents mental strain, stress, and overextension.

 

### Gaining ⊖Fatigue

A character may gain ⊖Fatigue from:
- Overspending ⚡︎Energy and choosing Fatigue as the cost.
- Prolonged stress, deprivation, or psychological pressure.
- Specific Abilities or effects.
- Narrative strain at GM discretion.

 

### Maximum ⊖Fatigue

Maximum ⊖Fatigue = 1 + ☼Resolve Modifier.

If a character would exceed their maximum ⊖Fatigue:
- They immediately fall **Unconscious**.
- They fall prone.
- They cannot take ✦Actions, ✻Activities, spend ⇉MP, or use Reactions.

They remain Unconscious until their ⊖Fatigue is reduced below maximum.

 

### Effects of ⊖Fatigue

Each ⊖Fatigue imposes a cumulative penalty:
- -2 to ◉Awareness
- -2 to ∞Intuition

These penalties stack.

Fatigue does not directly reduce Defense values unless specified by another rule.

 
 

## Unconscious State

A character who is Unconscious:
- Falls prone.
- Cannot act.
- Cannot move.
- Cannot use Reactions.
- May still be targeted normally.

Unconsciousness does not grant automatic immunity or resistance unless defined by a system built on top of Frontiers.

Regaining eligibility to act immediately ends the Unconscious state.

 

### Stabilizing an Unconscious Character

An ally adjacent to an Unconscious character at 0 ✚HP may spend **2 ✦AP** to stabilize them. This restores the Unconscious character to 1 ✚HP.

The ally must be in melee range (1 ⌗Unit or able to physically touch the target).

The ⊗Wound that was gained when the character fell to 0 ✚HP **remains**. Stabilization restores the character to acting condition; it does not remove the injury.

 
 

## ⏾ Downtime

⏾Downtime represents structured rest and recovery outside active pressure.

Downtime may occur:
- Between Encounters
- During travel
- In secure locations
- At the GM's discretion

 

### Downtime Recovery

For each uninterrupted hour of ⏾Downtime:
- Regain 1 ⚡︎Energy.
- Remove either 1 ⊗Wound **or** 1 ⊖Fatigue.

A character cannot remove both a Wound and a Fatigue in the same hour.

For each 3 uninterrupted hours of ⏾Downtime:
- Regain 1/2 of maximum ✚HP.

This stacks at rolling intervals: 3 hours = 50% HP, 6 hours = 100% HP. ✚HP cannot exceed maximum.

 

### Interrupted Downtime

If Downtime is interrupted by:
- Combat
- Immediate danger
- Significant exertion

Recovery for that hour is lost. Time must be restarted for recovery to resume.

 
 

---
 
 

## Tuning the Feel

The default rules give Frontiers' baseline feel. The knobs below let designers tune that feel without breaking the engine.

 

### Action Economy Tuning

The 3 ✦AP per Turn default produces medium-paced tactical play.

| AP per Turn | Produces | Good for |
|---|---|---|
| 2 | Tighter decisions, faster turns | Lethal or low-resource systems |
| 3 (default) | Balanced tactical depth | Most Frontiers-based systems |
| 4 | Richer combinations, longer turns | Heroic or power-fantasy systems |

Changing this requires recalibrating Ability AP costs across the board.

 

### Energy Pressure Tuning

How often Energy gets spent shapes the entire feel of Encounters.

- **Generous Energy** (high max, slow drain): Players use Abilities freely. Encounters feel powerful but lower-tension.
- **Default Energy**: Players choose when to push. Most Encounters can be played without Overspend; major Encounters force decisions.
- **Scarce Energy** (low max, fast drain): Every Ability use is a calculation. Overspend becomes common. The system feels harsh.

 

### Lethality Tuning

Frontiers' lethality is tuned through:
- Starting ✚HP scaling
- Damage values per attack
- Maximum ⊗Wounds (1 + ❖Vigor Modifier)
- Whether characters auto-revive at Encounter end

Tightening any of these makes the system more lethal. The auto-revive rule is the strongest single lever. Removing it makes Wound counts the primary survivability gate.

 

### Initiative Tuning

The default Initiative system (base + Finesse adjustment) supports build identity. Variants:

- **Fixed Initiative.** Skip the Finesse adjustment. Faster setup, less tactical.
- **Rolled Initiative.** Roll d20 + Finesse Modifier. More volatile, rewards luck over planning.
- **Side-Based Initiative.** All allies act, then all enemies. Fastest, removes per-character ordering.

 

### Healing Pace Tuning

The default healing rate (3 hours = 50% HP, rolling) is moderate.

- **Faster healing.** 1 hour = 25% HP, rolling. Recoveries between Encounters become trivial.
- **Slower healing.** 8 hours = 50% HP. Single full rests become major events.
- **Per-hour granularity.** 1 hour = (1/8) maximum HP. More tracking, finer control.

 
 

---
 
 

## Edge Cases

The following rulings apply unless a specific rule explicitly overrides them.

 

**Skipped Turn Due to Incapacitation.**
If a participant is Unconscious or otherwise unable to act at the start of their Turn:
- Their ✦AP and ⇉MP still refresh.
- They cannot spend them while incapacitated.
- Their Turn immediately ends.
- Unspent ✦AP and ⇉MP are lost as normal.

Start-of-Turn and End-of-Turn effects still resolve.

 

**Simultaneous Start-of-Turn Effects.**
If multiple effects trigger at the start of a participant's Turn:
- The active participant determines the order of their own effects.
- If effects belong to multiple participants, resolve the active participant's effects first, then others in Initiative order.

 

**Simultaneous End-of-Turn Effects.**
If multiple effects trigger at the end of a participant's Turn:
- The active participant determines the order of their own effects.
- Other participants' effects resolve in Initiative order.

 

**Reaction Chains.**
If multiple Reactions are triggered in response to the same event, resolve them in reverse chronological order:
- The most recently declared Reaction resolves first.
- Continue resolving Reactions in reverse order of declaration.
- The original triggering Action resolves last unless interrupted by a rule that explicitly cancels it.

Initiative does not determine the order of Reactions within a chain.

 

**Interrupting Effects.**
Unless a rule explicitly states that an effect interrupts:
- An Action fully resolves.

No effect retroactively cancels a resolved Action unless the rule explicitly states it does.

 

**Overspend and Immediate Incapacitation.**
If a character Overspends ⚡︎Energy and the gained ⊗Wound or ⊖Fatigue causes them to reach maximum:
- They immediately fall Unconscious (or die if Wounds exceed maximum).
- If this occurs during their Turn, their Turn ends immediately.
- Any unspent ✦AP or ⇉MP is lost.

The Ability or effect that caused the Overspend is still considered resolved unless a rule states otherwise.

 

**Damage While Down During Resolution.**
If a character is reduced to 0 ✚HP during an Action:
- The Action finishes resolving.
- The character then gains a ⊗Wound and falls Unconscious.

If damage occurs during a multi-step effect, resolve the triggering step fully before applying Unconsciousness.

 

**Leaving Encounter Play Mid-Round.**
If the Encounter ends during a participant's Turn:
- The current Action finishes resolving.
- The current Turn ends.
- All unspent ✦AP and ⇉MP are lost.
- Timing returns to Free Play structure.

Ongoing effects persist according to their duration.

 

**Entering Encounter Play Mid-Action.**
If Free Play transitions into Encounter Play during an unresolved Action:
- Resolve the current Action fully.
- Establish Initiative.
- Begin a new Round.

No participant begins the Encounter with expended ✦AP or ⇉MP.

 

**Movement During Another's Turn.**
If a participant is moved during another participant's Turn:
- The movement resolves immediately.
- It does not grant additional actions.
- It does not alter Turn order.

If movement places them into or out of range of an ongoing effect, apply the new positioning immediately.

 

**Energy Recovery During Encounter Play.**
⚡︎Energy cannot be recovered during Encounter Play unless a rule explicitly states otherwise.

⏾Downtime recovery cannot occur while structured timing is active.

 

**Multiple State Changes Simultaneously.**
If a character would simultaneously reach maximum ⊖Fatigue, reach maximum ⊗Wounds, and drop to 0 ✚HP, resolve in this order:
1. Apply damage and reduce ✚HP.
2. Apply ⊗Wounds.
3. Apply ⊖Fatigue.
4. Determine death or Unconsciousness.

This prevents circular dependency between state systems.

 

**Zero Movement Points at Turn Start.**
If a participant begins their Turn with 0 ⇉MP due to an effect:
- They still receive refreshed ✦AP.
- They may still perform ✦Actions unless otherwise restricted.

 

**Zero ✦AP at Turn Start.**
If a participant begins their Turn with an effect that prevents spending ✦AP:
- Their Turn still occurs.
- Start-of-Turn and End-of-Turn effects still resolve.
- They cannot declare ✦Actions.

 
 

---
 
 

## Variants

Variants preserve the core structure of Frontiers' Flow of Play. They change *implementation*, not *philosophy*.

 

### 2 AP Variant

**What changes:** Participants begin each Turn with 2 ✦AP instead of 3.

**What stays:** AP refresh timing, Reaction rules, Free Action rules.

**What shifts:**
- Tighter decisions, faster turns.
- Ability AP costs must be recalibrated. 1-AP abilities become much stronger; 3-AP abilities become turn-locking.

**Use when:** Building a lethal or fast-paced system where every Turn should feel like a sharp choice.

 

### Reaction Limit Variant

**What changes:** Each participant may use only one Reaction per Round, regardless of available ✦AP.

**What stays:** Reactions still cost ✦AP from the current Round.

**What shifts:** Removes reactive build dominance. Caps the engine's reactive ceiling.

**Use when:** A system wants to prevent reactive abilities from stacking, or wants Reactions to feel rare and special.

 

### Action-Based Movement Variant

**What changes:** Remove ⇉MP. Movement costs 1 ✦AP per 2 ⌗Units moved.

**What stays:** ⌗Units, forced movement rules.

**What shifts:**
- Simplifies resource tracking.
- Movement now competes directly with Actions. Slower characters become tactically inefficient, not just slow.
- Reduces build identity for movement-focused characters.

**Use when:** A system prioritizes simplicity over build differentiation.

 

### Zone Movement Variant

**What changes:** Replace ⌗Units with abstract Zones (Engaged / Near / Far). Moving between adjacent Zones costs 1 ⇉MP.

**What stays:** ⇉MP refresh timing, forced movement rules.

**What shifts:**
- Speeds play significantly.
- Reduces grid reliance.
- Loses fine positional control. Flanking, area effects, and range become approximations.

**Use when:** Building a narrative-forward system where exact positioning matters less than relative position.

 

### No Overspend Variant

**What changes:** If a character lacks sufficient ⚡︎Energy, the Ability cannot be activated. Negative ⚡︎Energy does not exist.

**What stays:** Energy recovery, Fatigue from other sources.

**What shifts:** Removes the risk-reward tension of Overspend. Simplifies bookkeeping.

**Use when:** A system wants Energy as a hard ceiling rather than a soft barrier.

 

### Conscious at 0 HP Variant

**What changes:** When reduced to 0 ✚HP, the character gains a ⊗Wound but remains conscious. They:
- Cannot spend ✦AP.
- Cannot spend ⇉MP.
- Suffer -4 to all Resolution Rolls.

They fall Unconscious only on a second ⊗Wound at 0 ✚HP.

**What stays:** Wound maximum rules, death threshold.

**What shifts:** Allows dramatic last stands before collapse.

**Use when:** A system wants heroic endurance moments.

 

### Gradual Wound Severity Variant

**What changes:** Wounds impose escalating penalties:
- 1st Wound: -1 Defense
- 2nd Wound: -2 Defense
- 3rd Wound: -3 Defense
- (Continues escalating per Wound)

**What stays:** Wound maximum, death rules.

**What shifts:** Creates nonlinear survivability decline. Characters feel fine until they're suddenly not.

**Use when:** A system wants combat to feel survivable until it breaks.

 

### Granular Downtime Healing Variant

**What changes:** Replace the rolling 3-hour-per-50%-HP rule with per-hour healing.

Suggested rate: 1 hour = (1/8) maximum HP, rolling.

**What stays:** Wound and Fatigue removal rates (still 1 per hour).

**What shifts:**
- Finer healing granularity.
- Slightly more bookkeeping.
- Encounters that pause for short rests recover meaningful HP.

**Use when:** A system wants short-rest mechanics or finer time-based recovery control.

 
 

---
 
 

## Alternatives

Alternatives replace major aspects of the Flow of Play architecture. Adopting these requires recalibration of Abilities, scaling, and pacing assumptions.

 

### Simultaneous Turn Alternative

**Core change:** Remove individual Turns. Each Round:
1. All participants declare Actions.
2. Resolve in Initiative order.
3. Apply all results before the next Round begins.

✦AP still refreshes per Round.

**What you gain:** Cinematic chaos. No participant feels singled out.

**What you lose:** Strict turn segmentation. Tactical clarity. Players can no longer plan in response to others' actions.

**Use when:** Building a system that emphasizes simultaneous, ensemble action.

 

### No Initiative Alternative

**Core change:** Remove Initiative entirely. Turn order rotates clockwise around the table, with the GM inserting NPCs logically.

**What you gain:** Maximum simplicity. No setup at the start of Encounters.

**What you lose:** Speed-based ordering. Builds that emphasize tempo lose mechanical expression.

**Use when:** Building a rules-light system where Initiative tracking adds friction without adding value.

 

### Unified Resource Alternative

**Core change:** Remove ✦AP entirely. All Actions cost ⚡︎Energy.

At the start of each Round, regain 3 ⚡︎Energy automatically. Reactions cost additional ⚡︎Energy.

**What you gain:** Single resource to track. Energy becomes the universal pressure currency.

**What you lose:** The distinction between routine effort (AP) and strain (Energy). Combat becomes a constant Energy budget exercise.

**Use when:** Building a system where exhaustion is the central pressure.

 
 
---
 
 

## A Note to System Designers

Flow of Play is the system players touch most often. Every Encounter, every fight, every chase passes through it. Get it wrong and the game feels fiddly or sloppy. Get it right and players stop noticing the rules entirely.

A system that adopts Frontiers' defaults inherits a particular feel:
- Two clean modes with one consistent grammar
- Tactical depth without grid-locked complexity
- Reactive builds that pay a real cost
- Pressure resources that mean something

This feel is deliberate and tuned.

Modifying the defaults with a Variant or an Alternative changes that feel. That is legitimate. Frontiers is a tool, not a religion. But modify intentionally. Action economy choices ripple outward into every Ability, every Encounter, every character build.

Like everything in Frontiers, you are open as a designer to massively modify what Frontiers offers in favor of a method that works best for your system. This document is just giving you the tools and concepts Frontiers considered when deciding its own default engine rules.

 

---

*For the engine's broader design philosophy, modularity, the Variant and Alternative convention, and how to build on Frontiers, see [**Designing With Frontiers**](https://hackmd.io/@frontiers-engine/Designing_2026-2).*

*For the condensed working ruleset, see the [**Frontiers Overview**](https://hackmd.io/@frontiers-engine/Overview_2026-2).*