# World systems

**Setup** decides what kind of game this is. Several toggles here remove whole steps from
the editor, so it is worth understanding before you wonder where a step went.

> **Image: `docs/setup-advanced.png`**
> The Setup step's Advanced Options panel showing the Game Systems toggles.

## Game systems

| Toggle | What it decides |
|---|---|
| **Combat** | Whether fighting exists. Off hides the Creatures step. |
| **Abilities** | Whether characters have abilities. Off hides that step. |
| **Rolls** | Whether outcomes are decided by dice at all. |
| **Stats** | Whether characters have numeric attributes. |
| **Encyclopedia** | Whether long-form lore is retrieved for the narrator. |
| **Weather** | Whether the world has changing conditions. |
| **Time system** | Whether the world runs a clock. |

Turning one off does not delete your data — turn it back on and the step returns intact.

## Time, and games without it

The **Time System** decides whether the world has a real clock: hours per day, minutes per
hour, day names, a starting time.

A game **without** a clock still passes time in a loose sense — the narrator estimates how
long a turn took. That estimate is fine for prose and wrong for arithmetic, which matters
if you later write rules; see [Minutes are not time](/docs/minutes-are-not-time).

## Narration and enforcement

**Impossible actions** and **Invented items** control how strict the narrator is about
players trying things the world does not support. Loose is more fun; strict is more
coherent. Most games want something in between.

**Roll manipulation** decides whether players can influence their own rolls.

## NPC behaviour

**NPC simulation**, **NPC control** and **NPC background combat** decide how much life the
world has when players are not looking — whether NPCs act on their schedules, whether
players can direct them, and whether fights happen off-screen.

These cost turn time, so a small game may want them off.

## Stats and the HUD

**Stat sets** define your game's attributes. Rename them freely — rules read stats by
*role*, so a stat called "Thew" still answers to the might role and nothing breaks.

The **HUD editor** decides what players see at a glance. A survival game shows hunger; a
courtly intrigue shows reputation.

## Calendar and weather

**Calendar** sets day names and the shape of a year. **Weather cycles** decide what
conditions occur and how they move — which locations can then override
([Locations](/docs/locations)).

## Next

- [Shops and loadouts](/docs/shops)
- [Publishing](/docs/publishing)