Fields

A field is a value your plugin puts on things: satiety, infection, mana. Declaring one is usually the first thing a plugin does.

What a declaration gives you

• a range (min and max). Every write is clamped to it.
• tiers: what the narrator says at each band, and what the HUD badge shows.
• visibility: a row on the sheet by default, or a HUD bar.
• optionally, a creation question asked when a player builds their character.

Tiers are what the narrator sees

The narrator never sees the number. It sees the tier prose:

Band	Narrator reads
0-3	nothing
4-9	"a fever rides him"
10-14	"veins darkening at the wrist"
15+	"barely lucid, burning to the touch"

Write tiers as something a narrator would say in the scene. "infection: 12" isn't a tier.

Leave the resting tier silent. Otherwise every turn carries a status report.

Bands: absolute or ratio

• No max: bands are absolute values.
• With a max: bands are a fraction of the max.

If your tiers look wrong, check whether you meant to set a max.

Who carries it

Trait	Lands on
entity	everything that moves: players, NPCs, creatures, items
living	players, NPCs, creatures
carryable	items
player / npc / creature	one kind only
location	the place itself

entity does not include locations. A location field is how a place tracks its own state: how corrupted this crypt is, how much game is left in the forest. Read it with $.location.fields.corruption or $.field('corruption', 'location').

Reading

$.field('infection')              // the subject
$.field('infection', 'target')    // whoever was aimed at
$.field('corruption', 'location') // the place

Missing reads as null, not 0. See Missing values.

Derived fields

A field with a valueExpr is computed when read, not stored, like a carry limit worked out from might. You don't write to it. Because nothing is stored, $.hasField() says false for it, so branch on its inputs instead.