In Dungeon World and many other PbtA games, “When a player describes their character doing something that triggers a move, that move happens and its rules apply.”
That sounds simple enough. Except that the triggerspace (all the actions that trigger moves) changes over time and play—
- As PCs level up, they add new moves from their playbook to the current triggerspace. And, as they grow fictionally, they can be awarded new moves. In Stonetop, playbooks can be expanded with inserts after specific fictional events befall them (i.e., becoming a ghost, thrall, or revenant); in Dungeon World, playbooks can be expanded through compendium classes, also triggered by fictional events (e.g., becoming a vampire or a dragonslayer).
- As PCs leave the game and are replaced, their old playbook moves vanish from the triggerspace, and new playbook moves come in.
- As PCs travel to different locations, environmental moves come and go: for instance, travel moves only make sense on the road, and settlement moves only make sense in a settlement. The GM may be using an adventure starter or their own custom moves that come into play in very specific locales: the pickpocket move when Stonetop PCs visit Marshedge, for example (“When you go unwary into the bustle of Edgemarket or the crowded streets of Dropoff, roll +WIS: on a 10+, you spot the pickpocket coming or catch them in the act…”).
- As PCs’ circumstances change, other moves come and go; for instance, recruiting a hireling brings in the follower moves, which go away if the hireling is lost; downtime moves only make sense during downtime; etc.
Since the inventory of available moves is variable and changes over time, Dungeon World in particular encourages everyone to look for moves: “Everyone at the table should listen for when moves apply. If it’s ever unclear if a move has been triggered, everyone should work together to clarify what’s happening. Ask questions of everyone involved until everyone sees the situation the same way and then roll the dice, or don’t, as the situation requires.”
This is fine for common moves. One difficulty is typically only the player has access to their playbook with their current moves. Sometimes an experienced player might remind another, but usually each player is on their own at identifying the right moves for themselves. We’ve certainly had occasions where later in the session a player will say, “Oh, I should have used _____.”
Given the complexity of the triggerspace, it’s no surprise that moves that should have been triggered are sometimes skipped, or that even the wrong move is triggered. It’s one of the reasons I like having a catch-all move to fall back on in the heat of play.
Freebooters on the Frontier 2e does the best job I’ve seen of visually displaying the common triggerspace, grouping and listing the triggers on its GM screen:
Freebooters 1e was outstanding for how it grouped moves, an architecture I adapted for Uncommon World and have now seen in other fantasy PbtA games. Grouping moves helps make the trigger space easier to navigate.
Some games vary tremendously in the size of their moveosphere. For instance, Hard Knock World has only 20 moves in total: 1 catch-all move, 8 common moves, 6 class moves (one per class), plus 5 background moves (one per background). Dungeon World as expanded by the community, with all its custom playbooks and compendium classes, has literally thousands of potential moves, though in any given game this will be a few dozen moves in the current triggerspace.
In contrast to the triggerspace, think of the rulespace of 5e, where triggers aren’t explicit, and players have to bring up the relevant rules for a situation, often drawn from across many different books. This was one of the reasons I switched from 5e to Dungeon World. My players were pulling in rules from beyond the three core books: from Xanathar’s Guide to Everything, Wayfinder’s Guide to Eberron, Volo’s Guide to Monsters, and various Unearthed Arcana.
The Bakers’ latest published game, Under Hollow Hills, removes the idea of triggers being latent aspects of the gamespace that must be used. Instead, the player has discretion about which move they want to use.
If you’re designing a PbtA game, carefully consider how best to represent the common triggerspace and how to make it easier to navigate during play. If you’re playing a PbtA game which doesn’t provide a good overview of its triggerspace, consider creating and sharing one!