Running the Game
Momenta Core Rules · Moment 5 · Missions and Campaigns · Chapter 27
The rules in Moments 1 through 4 are shared between players and the GM. This Moment is the GM’s: how missions are built, how progress is rewarded, and how encounters are designed. Before the procedures, three principles that the whole book leans on.
The fiction-first test
Many rules ask whether something plausibly applies: a Thread to a roll, a Bond to an action, a mastery’s flavor to a situation. The test is always the same — the player explains it, and you decide whether the explanation holds. A good explanation is the price of the benefit. A thin one means the benefit doesn’t fire, and nothing is spent. Be generous with players who are telling the truth about their characters, and firm with players who are reaching for dice. Over time, the table learns what “plausibly” means at your table, and that is exactly the point: it is a taste you set together.
The GM adjudicates
Wherever the book says the GM adjudicates, it is handing you a decision on purpose rather than writing a rule that would be wrong half the time: line of sight through a crumbling wall, whether a jump is a Move or a stunt, what a nemesis’s curse takes to lift. Three habits make these calls feel fair:
- Rule fast, revisit later. A quick call keeps the scene moving; write down anything you want to reconsider, and settle it between sessions rather than mid-fight.
- Favor the fiction. When two readings are equally defensible, choose the one the story is asking for.
- Be consistent. The same situation should get the same call next week. Your past rulings are house rules; treat them that way.
Working the loop
The Loop of Play describes the shape of the game (see The Loop of Play); running it means choosing when to switch halves.
Call combat when positioning and pacing matter — when where people stand and how fast things happen will change the outcome. Ambushes, standoffs, and chases are combat. A back-alley threat that a good line resolves is a scene.
End combat on the objective, not on the last enemy. When the encounter’s objectives are achieved or lost, say so and put the grid away — surviving enemies flee, surrender, or simply stop mattering. See Building Encounters.
Cut to an interlude when the party has earned a breath and the story has a beat to offer: the aftermath, the argument, the quiet moment before the next door. See Interludes.
Use the clocks. The mission clock is how the campaign’s stakes reach the table, and Momentum is how the party’s confidence does. Let both be visible; players make better decisions when they can see the pressure. See The Mission Loop and Momentum.
Narrative play from the GM’s chair
Set difficulty from the ladder honestly, describe what failure costs before the dice hit the table, and let “Success at a Cost” do its work — it is the most common outcome in the game and the engine of most of its stories. Group rolls are for moments the whole party shares; use Carry to let a strong character cover a weak one, and let the consequences land on someone. See Narrative Actions and Clocks.
Enemies are yours
Enemy stat blocks are written to be run fast: scripted defenses instead of reactions, fixed successes for the rank-and-file, tactics lines that tell you what they want. Use them as written until you know the game, then reskin freely — the challenge-class templates exist so that a new monster is a few minutes’ work. See Building Encounters.