Four sections, fourteen pieces

Every rulebook is an answer to the same question: who at the table may declare that something is true in the fiction. These pieces follow that question from the wargame umpire who inherited it to the player-facing move that tried to write it down.

• Who gets to say it happened?

  Every roleplaying system is an answer to one question — how a table shares authority over what is true in the fiction.

• The referee inherits a wargame

  The role came out of umpiring, where somebody adjudicated what the rules did not cover.

• Player-facing rules, and what they move

  Putting the roll in the player's hands changes who carries the burden of knowing the system.

Four sessions, spread across four decades, after which the job of a rule was not what it had been. Braunstein and Lake Geneva at one end; Apocalypse World and the return to 1974 at the other.

• Braunstein

  A wargame in which players were given individual characters and objectives rather than armies, and the session ran away from its own rules.

• Lake Geneva

  The dungeon campaign that put single characters into a medieval wargame and produced something with no win condition.

• Apocalypse World

  A system built on moves and player-facing rules that rebuilt the procedural layer around conversation.

• The OSR argument

  Returning to the 1974 assumptions is itself a design position about where authority should sit.

The visible half of a resolution system is a probability shape, and the shape decides how often a table is surprised. Four pieces on what each one buys, what it costs, and why two games with the same target number do not feel alike.

• What the dice are actually doing

  A resolution system is a probability distribution with a story attached, and the shape of the curve decides how often the unlikely happens.

• d20 against 3d6

  Flat against bell: one makes every outcome equally likely, the other makes the middle ordinary and the edges rare.

• Roll-under, and the appeal of a number you already know

  Testing against a stat the player already has removes a layer of arithmetic from every check.

• Dice pools: many small chances instead of one big one

  Counting successes across a handful changes the texture of failure as much as its frequency.

Initiative, the exploration turn and the reaction roll are the parts nobody quotes. They are the machinery that keeps exploration a system rather than a description.

• The layer nobody notices

  Initiative, the exploration turn and the reaction roll are what stop a session becoming an unstructured conversation.

• The reaction roll

  Deciding an encounter's disposition by dice removes it from the referee's mood, which is a deliberate transfer of authority.

• The exploration turn

  A unit of time that makes resources tick — light, rations, wandering checks — and turns exploration into a system.