Writing Custom Moves

Player moves are little blocks of rules that kick in at certain times and say what happens. You might write custom ones to handle a specific situation, to flesh out a threat or site or arcanum, to give a PC new options, or to tweak how the game runs at your table.

Before you draft anything big — a new playbook, insert, or major arcanum — actually play or run a lot of Stonetop. Study the existing moves: how they're shaped, how they interact, what they can do.

1. Take stock. What does the move model — a situation, an ability, a question to answer? What constraints do you have (space, time, your group's preferences)? What are your goals — push players into interesting choices, grant permission, explore feelings, establish stakes, embellish play, reinforce a theme? And do you actually need a move? If you'd resolve the situation fine with the core loop and existing moves, you've saved yourself work.
2. Draft the trigger. Usually "when you do X" or "when X happens." Triggers can also fire on other moves, on roll results, on real-world player actions, on conditions met, or when a player wants them to. Multiple triggers make sense for moves with phases (Wards & Bindings) or multiple related effects (Recover). Watch for triggers that are too broad — Clash originally read "when you attack a foe" and applied to foes that couldn't fight back; it was rewritten to "when you fight."
3. Brainstorm results. What definitely happens? What might happen, good or bad? Results can be fictional (something becomes true), mechanical (HP, debilities, bonuses), or player-level (questions asked, feedback given). They can be immediate, ongoing, delayed, or combinations. Consolidate similar ones, identify mutually exclusive ones, and split into definitely/maybe-good/maybe-bad lists.
4. Decide how you pick between results. A roll for uncertainty. Player picks for agency. Target picks (other PC's player, or you for NPCs) to preserve integrity. GM picks sparingly. Procedure based on fiction or mechanics. Consensus for whole-group moves like End of Session. Mix and match.
5. If there's a roll, decide how it works. Define a 6- only when you have a real reason (like Death's Door's three outcomes, or Trade & Barter's low-stakes failure). Default is +STAT but you can build the modifier from things that are true ("+1 if you bring a possession of the deceased") or skip stats entirely (Death's Door rolls +nothing). Tiers can break from 10+/7-9/6- — Haggle has 12+ for true success, Howling Curse inverts so 10+ is the worst result. Try alternative roll structures (Die of Fate, risk rolls, dice pools, rolling against current HP) when they fit.
6. Write a full draft. Don't worry about polish yet. Pick lists for 3+ options (and even 2 for clarity); keep them to 2-4 ideally. Make options parallel in scope, scale, timeframe. Use "else" statements when one option implies the absence of another.
7. Review and revise. Imagine it in play with multiple outcomes. Check goals and constraints. Cut bad patterns: outcome confused with intent ("when you solve" should be "when you try to solve"), player mechanics applied to NPCs (no "they mark dazed" — translate to a fictional limitation), references to "rounds" or "turns" (use fictional equivalents), boring results that amount to "try again," overly defensive legalistic language. Punch up the language. Edit for length. Get feedback.

A move you'll use once doesn't need to be perfect. You can revise it after seeing it in play.