Flow of Play¶
This document is part of the Frontiers Design Documentation, a set written to teach instead of to instruct. Each entry takes one subsystem, explains what that subsystem 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 Flow of Play¶
Flow of Play is how a game moves time: where it slows down and counts, and where it lets time pass freely. Most systems answer this by defining a handful of distinct modes of play, each with its own rules and its own tempo.
To give a well-known example, Pathfinder is probably the clearest case most designers have already read. Paizo splits play into three named modes and gives each its own procedure.
- "Encounter" mode. Time is counted. Initiative order, turns, a fixed budget of actions each round.
- "Exploration" mode. Time is loose. Characters move, search, and travel, and the group commits to activities and not actions.
- "Downtime" mode. Time is long. Days or weeks pass while characters craft, earn, recover, or train.
That is Paizo's answer to the Flow of Play question, and stating it that plainly makes the question itself visible. The fiction runs continuously while play does not. Somewhere the game has to decide where it slows down and counts, and where it lets time slide.
Flow of Play is the Frontiers term for that decision. The field has no settled name for it. Some games call them modes or phases or play states, and many never name it at all, handling it entirely inside their combat rules. The territory is the same regardless of the label:
- How time is segmented, and whether the segments are named.
- How much a character can do inside a segment.
- What moves play from one segment to another.
Why it matters before anything else¶
Flow of Play is the top-level structural question, and nearly every other rule sits downstream of it. Three examples of that dependency:
An Action Economy (the rules that decide how much a character can do before play passes on, most often inside combat-style modes) only means something once you have decided that some part of play is counted in turns. Without a counted mode there is no unit for it to meter, and the rules have nothing to attach to.
A Travel system only means something once there is a mode that moves in hours or days, not seconds. Supply, navigation, and wear are all costs paid over distance, and a mode counted in single actions cannot hold them.
A Crafting system only means something once there is a mode long enough to contain the work. Building something worth building takes days or weeks, so a game without a long-scale mode either abstracts crafting into a single roll or has nowhere to put it at all.
That leaves a lot of weight resting on one early decision, which is why the field has never settled on a single accepted answer.
Do not let that dissuade you. Get the modes feeling good and the rules attached to them stay small, because each one only has to work inside its own segment. Get them wrong and you end up with rules that fire at the wrong tempo, or subsystems with nowhere to sit.
However, the choice here also has a subtextual effect on the game. The modes or states of play with the most content tied to them will often be what most players remember about the system, or, in a way, what the system values. A game with three pages of combat procedure and one paragraph on travel has told you what it prioritizes, whatever its introduction claims.
For the designer, the question underneath all of it is:
How do you want play to progress, and how many distinct kinds of play are you actually catering to?
Answer that and the rest of the engine has a shape to grow into.
The Approaches¶
No number of modes is the correct one, and the tradeoff runs legibility against overhead. Every mode you name is one you have to explain, write rules for, and teach a table to recognize. Every mode you leave unnamed is one the table has to improvise.
While I cannot cover every possible variation in this document, there are a few examples laid out below that you may find shades of familiarity with.
One counted mode¶
The game defines combat precisely and leaves the rest as conversation. Initiative (the rule that decides who acts when, once time is being counted), turns, and action budgets are reserved for the fight. Travel and downtime exist in the fiction, sometimes with scattered rules, but are never named as modes with procedures of their own. Systems built off the 5e SRD often use this method, to various levels of success.
Efficient, and common for good reason, since the tightest rules sit where the stakes are highest and everything else stays fast. The cost is that play outside the counted mode inherits no structure, so it runs on GM improvisation, and works far better with an experienced GM than without one.
Named modes¶
Blades in the Dark names its phases outright: "Free Play" for open scenes between jobs, "The Score" for the heist itself, and "Downtime" for recovery, long-term projects, and vice. Each carries its own procedures, and the table always knows which one is in scope. Ironsworn reaches a similar effect by grouping its moves around situations, so the set of moves in play tells you what kind of scene you are in. And, as mentioned earlier, Pathfinder's "Encounter", "Exploration", and "Downtime" modes are the same idea in a more traditional frame.
Naming them buys clarity. A table knows what a session is supposed to contain, non-combat play feels genuinely supported instead of improvised, and the GM has a pacing structure to lean on. It costs learning time up front, and it can turn rigid at the seams, since a scene sitting between two modes needs someone to rule which procedures apply.
Scene-based framing¶
Fate and much of the Apocalypse World family attach mechanics to situations rather than to segments of the clock. Play is framed scene by scene, meaning the group cuts to what matters and skips what does not, instead of tracking time continuously.
The two get there differently. Fate escalates by situation type: an ordinary exchange resolves as a single roll, while a "Contest" or a "Conflict" brings in exchanges and turn order when the stakes justify it. Apocalypse World never counts time at all, and lets "Moves" do the work: the fiction runs as conversation until someone does something that triggers a Move, and the trigger itself is what marks the moment as mechanically live.
It is the most flexible shape and the least legible, since nothing in the rules announces when to slow down and the GM ends up carrying it.
Granular procedures¶
Torchbearer and its exploration-focused relatives go further, giving several activities their own economies instead of one shared clock. Adventuring runs on Dungeon Traversal (a fixed unit of exploration time, usually paired with a cost like light or food so that delay itself becomes a decision), while camping and returning to town each have separate procedures with their own costs and recovery rules.
Resource pressure therefore never lets up, it only changes shape. Depth is the payoff, and each activity feels genuinely distinct instead of a reskin of the last. But each procedure is a rule set to write and remember, and past a point they compete for the same play time.
You could define fifteen modes. It would work, and you would then have to justify fifteen, teach fifteen, and keep them from bleeding into each other. You could define none, which also works, and hands the improvisation to your table. Most games land on two to four. Not because that is right, but because it is where modes stay distinguishable without becoming a syllabus.
What Frontiers Does¶
Now, with that overview to catch you up to speed, here is the approach Frontiers takes, and the reasoning that led there.
Frontiers defines three modes of play, distinguished by how much time a unit of play represents:
| Mode | Time Scale | What can be done |
|---|---|---|
| Encounter | Seconds | ✦ Actions |
| Exploration | Minutes | ✦ Actions and ✽ Activities |
| Endeavor | Hours to days | ✽ Activities |
Only the Encounter carries a counted economy. Exploration and Endeavor are unmetered: characters do things, and rolls happen when an outcome is uncertain, but nothing tracks a budget. Full rules live in the Rulesets; what follows is why the shape looks like this.
Three modes, borrowed openly¶
I like what Pathfinder does here, and Frontiers takes it more or less intact. Three tempos separate cleanly, and most people at a table already understand the structure without being taught it, so an engine meant to be built on does not have to spend its first lesson re-teaching something a designer gets for free. Borrowing it buys the reader a running start.
What Frontiers takes from it is the chassis. The three modes give a stable frame to hang a more precise question on, namely what kind of effort is possible at each tempo. That is where the changes start.
The ✦ Action and ✽ Activity split¶
This is the choice the rest of the subsystem is built around.
A recurring frustration with existing systems is how loosely "action" gets defined. Abilities are written as working in combat or out of combat without combat ever being defined as a state. Resources recover at the end of your turn, in games where it is never established whether turns exist outside a fight. These systems work in practice because tables paper over them, but a designer building on top inherits every ambiguity.
Frontiers splits the word instead:
- An ✦ Action is fast enough to happen inside a Round. Swinging a weapon, activating an ability, vaulting a railing.
- An ✽ Activity takes longer than a Round. Studying a wall, searching a library, resting, crafting, traveling.
Every ✦ Action is also an ✽ Activity. Anything you can do in the space of a Round, you can do when you have longer, so ✦ Actions remain available in every mode. The reverse does not hold, and that is the useful part: reading a book is an action in the ordinary sense of the word, but you cannot meaningfully read one during a running gunfight, so it is an ✽ Activity and Encounters exclude it. An ability that lets you do it anyway becomes a real ability, with a clear thing it is overriding.
The payoff is two boxes to design in rather than one vague one. An Endeavor takes ✽ Activities only, an Encounter takes ✦ Actions only, and Exploration takes both, freely, because it sits between the two tempos. No rule ever has to say "in combat" and hope everyone agrees what that means.
Transitions are the table's call¶
Frontiers defines no procedural trigger for changing modes, which is intentional rather than unfinished.
The mode follows the tempo the fiction demands. Someone throws a punch, a train comes loose, a bomb starts counting down: you are in an Encounter, because the situation now turns on split-second decisions. When the pressure lifts, you are back in Exploration. When the group commits a day to a single pursuit, it is an Endeavor. The table recognizes the shift instead of the rules announcing it, and in practice everyone recognizes it at the same moment.
The cost is real and worth naming. Systems with procedural handoffs give a GM a rule to point at, where Frontiers gives them a criterion and trusts the table with it.
One resource, and movement outside it¶
The Encounter economy runs on a single pool of ✦ Action Points rather than the split budgets many traditional systems use, where a turn is divided into an action, a lesser action, and a move. Tracking three separate allowances in one turn creates bookkeeping, and more often it creates the sense that you are spending currencies which are not interchangeable for reasons nobody can articulate.
Unified pools solve much of that, and Pathfinder's is the version I most admire: one currency, spent as you like, with the shape of a turn falling out of what you can afford. Frontiers takes the same approach with two adjustments.
Movement sits outside the economy¶
A character has a ⇉ Movement budget separate from their ✦AP. You can move while swinging a sword; charging for both models something that is not physically true, and it makes moving feel like a tax on doing. Separating them means position is something you manage instead of something you buy.
Reactions draw on the same pool¶
Rather than a separate once-per-round allowance, acting out of turn is paid for from the same ✦AP a character would otherwise spend on their own Turn. That creates a genuine tension: spend everything now, or hold points back for something you cannot yet see coming. It ties a defensive posture to a real cost instead of handing it out free.
Is this the best solution for Flow of Play?¶
No, and no system's answer is. Flow of Play is a design problem the field has been arguing about for the better part of a century, and every solution surveyed above trades something away. Frontiers trades procedural certainty at mode transitions for flexibility, and trades some granularity for the ability to state plainly what an ✦ Action is.
What it is meant to be is a starting point, and a modular one. Official Frontiers systems will add to this layer, and so will other publishers, which is the intended use rather than a deviation from it.
There is a good chance you disagree with some of these answers, and that is a reasonable position to hold. The final section below sets out variant and alternative rules you can use in their place, along with what each one changes and what it will cost you elsewhere.
Variants¶
Variants keep the philosophy intact. Three modes, the ✦ Action and ✽ Activity split, and a counted Encounter all survive; what changes is how that Encounter is tuned. The groups below are dials instead of packages, and they are meant to be mixed. Take what suits the game you are building and leave the rest.
Tune the economy¶
The Encounter runs on 3 ✦AP per Turn, with ⇉ Movement held outside the pool. Both numbers are defaults, and both are safe to move.
Change the ✦AP count¶
Dropping to 2 makes Rounds resolve fast and gives every ✦ Action more weight. Raising to 4 or 5 opens room for combinations and longer sequences inside a single Turn, which suits systems with wide ability lists. Either direction sends you back to re-cost anything priced in ✦AP, and both shift the three-to-four Round pacing the engine is tuned around.
Fold ⇉ Movement into the pool¶
Paying ✦AP to move restores the move-or-strike decision and makes battlefield control abilities matter more. It is the most tactical single change available here, and the cost is the one the default was written to avoid: repositioning starts to feel like a tax on doing anything.
Return to split budgets¶
An action, a lesser action, and a move, tracked separately. Immediately familiar to most players and it guarantees a baseline of activity every Turn, at the price of three allowances instead of one and the return of the "why can't I spend this on that" question.
Tune the interrupts¶
Reactions draw from the same ✦AP pool as everything else, and ✧ Free Actions are capped at three per Turn. Both are levers on how much happens outside the normal flow of a Turn.
Give Reactions their own allowance¶
A separate once-per-Round Reaction makes defensive play consistent and predictable, and removes a thing to plan around mid-Turn. It also removes the spend-now-or-hold-back tension entirely, which is one of the more distinctive parts of the default.
Lift the ✧ Free Action cap¶
Fewer arbitrary limits to remember, and minor interactions stop competing with each other. In exchange, ✧ Free Actions become something to optimize, and item handling stops being a real constraint.
Tune the modes¶
Three modes is a starting point. Add a fourth if your genre needs one. Adding one is straightforward as long as it earns its own tempo.
Add a Travel mode¶
Pull travel out of Exploration and Endeavor and give it its own procedures for supply, navigation, and wear. Journeys become a mode of play, not a transition between them, which suits wilderness and survival games. The cost is a fourth set of procedures to write, teach, and maintain, competing for session time with the three that already exist.
Add a Social mode¶
Give extended negotiation, court intrigue, or interrogation its own structure instead of resolving it inside Exploration. Worth doing only if social conflict is a pillar of your game; otherwise it duplicates what Exploration already handles.
Mix freely. A grid-tactical system might fold ⇉ Movement into the pool and return to split budgets; a fast pulp system might drop to 2 ✦AP and hand Reactions their own allowance. None of these require changes outside Flow of Play.
Alternatives¶
Alternatives replace the philosophy, not tune it. Each one below changes what Flow of Play is in your system, and each reaches beyond this subsystem: the ✦ Action and ✽ Activity split is referenced by Abilities and Equipment, so anything that dissolves the split will require passes through those documents too. They are listed roughly in order of how far they travel from the default.
Two modes¶
Collapse Exploration and Endeavor into one uncounted mode. Encounters stay as they are; everything else is simply "not an Encounter," with long pursuits handled as narration.
This is the cheapest simplification available and it reads cleanly. What it costs is the tempo distinction that ✽ Activities depend on: without a long-scale mode, activities that take days have nowhere to live except GM fiat, and crafting or recovery systems lose the structure they were written against.
One counted mode¶
Define the Encounter and leave everything else as conversation. No named Exploration, no Endeavor, no ✽ Activity category at all. This is the dominant shape in traditional play and the one most designers will have absorbed by default.
It is efficient, and it puts all your rules where the stakes are. The tradeoff is the one surveyed earlier: everything outside the Encounter runs on GM improvisation, and abilities can no longer be scoped by mode, so any "out of combat" wording has to be defined some other way or left implicit. Choosing this means accepting the ambiguity Frontiers was built to avoid, in exchange for a considerably smaller rulebook.
Scene-based framing¶
Drop modes entirely and attach mechanics to situations, in the manner of Fate or the Apocalypse World family. Play runs as conversation, tightening only when a situation calls for a procedure, and time is whatever the fiction needs it to be.
This is the deepest cut in the list. Without modes there is no tempo to define ✦ Actions against, so the ✦ Action and ✽ Activity split dissolves, and with it the mode-scoping that Abilities rely on. Ability costs would need re-expressing as something other than ✦AP, most likely as fictional positioning or a resource of your own design. The payoff is a system that never stops to change gears, which is genuinely hard to achieve any other way.
Granular procedures¶
Go the other direction and give each activity its own economy: separate procedures for traversal, camp, town, and travel, each with its own costs and recovery rules, after the fashion of Torchbearer and its relatives.
Resource pressure never lets up under this model, it only changes shape, and each activity feels genuinely distinct, not a reskin of the last. The cost is volume. Every procedure is a rule set to write, balance, teach, and maintain, and past a point they compete for the same session time. This is the most work of any option here, and the most rewarding when the game is about the journey.
Whichever you choose, the rest of the engine is written to be recalibrated instead of replaced. A designer swapping Flow of Play wholesale should expect to revisit Abilities first, since it is the subsystem most tightly coupled to this one.