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Variables and Flags

Stalker PDA stories don't have a separate "quest database" — all state is stored in the same inventory and parameters as regular game items. This is a deliberate simplification of the engine, and it's worth understanding before designing a long story with many branches.

Flags as progress markers​

A flag is an arbitrary text string that the add action drops into the player's inventory, and that condition (has / !has) later checks. A flag has no icon and no weight — to the player, it's indistinguishable from a regular quest-log entry, if you name it well.

// "Accept the job" stage
"actions": { "add": ["sidorovich_job"] }

// A later stage checks progress
"transfers": [
  { "text": "How's the job going?", "stage": "stage_progress", "condition": { "has": ["sidorovich_job"] } }
]

// The stage that completes the job removes the flag
"actions": { "remove": ["sidorovich_job"], "add": ["job_reward"] }
Naming convention

Use clear, story-wide unique flag names (for example quest_sidorovich_started, quest_sidorovich_done) — these are snapshot-like markers, not typed variables, so a typo in the name will silently break a condition instead of throwing an error.

Numeric variables​

Besides flags, there are built-in numeric variables money and xp, plus your own variables, which you're free to introduce yourself — the engine stores them in the player's shared parameter map (parametersMap) and compares them with the operators =, !=, <, <=, >, >= (see conditions).

Numeric variables are handy where degree matters more than a plain fact: reputation with a specific character, a counter of "how many times the player lied," a trust level, resource-gathering progress, and so on.

"actions": { "add": ["Sidorovich_Trust:1"] }
"condition": { "Sidorovich_Trust>=": ["3"] }

Placeholders in Text​

Separate from state flags/variables, there are text placeholders like @name, which the engine substitutes into the text on the fly when it's shown to the player — they aren't stored as state, they just read the current profile data. The full list is in Stages and Dialogues.

How to design a story's state​

  1. For "yes/no" progress (picked up / not picked up, met / not met) — use flags via has/!has.
  2. For "how much" (reputation, counters) — introduce your own numeric variable.
  3. Don't reuse the same flag name across different, unrelated stories — state is shared at the level of the player's inventory, not isolated per story.
  4. Don't forget to "clean up after yourself": if a flag was only needed to track a single step, remove it with the remove action once that step is done — this makes debugging conditions on later stages much easier.