# destack:simulation/scenario

`import destack:simulation/scenario`

## Classes

- [Scenario](/docs/language/standard-library/modules/simulation/scenario/class/scenario/) — Active simulation scenario.

## Structs

- [Rule](/docs/language/standard-library/modules/simulation/scenario/struct/rule/) — Scenario rule definition.
- [ScenarioOptions](/docs/language/standard-library/modules/simulation/scenario/struct/scenario-options/) — Scenario construction options.
- [Trigger](/docs/language/standard-library/modules/simulation/scenario/struct/trigger/) — Scenario trigger controls.

## Newtypes

- [RuleId](/docs/language/standard-library/modules/simulation/scenario/newtype/rule-id/) — Stable scenario rule identifier.
- [ScenarioId](/docs/language/standard-library/modules/simulation/scenario/newtype/scenario-id/) — Stable scenario identifier.

## Type aliases

- [Activation](/docs/language/standard-library/modules/simulation/scenario/type-alias/activation/) — Scenario activation window.
- [Lifetime](/docs/language/standard-library/modules/simulation/scenario/type-alias/lifetime/) — Scenario rule lifetime.
- [Predicate](/docs/language/standard-library/modules/simulation/scenario/type-alias/predicate/) — Custom scenario trigger predicate.
- [Selector](/docs/language/standard-library/modules/simulation/scenario/type-alias/selector/) — Selector accepted by one scenario rule.

## Functions

- [always](/docs/language/standard-library/modules/simulation/scenario/function/always/) — Create a trigger that fires on every matching attempt.
- [binding](/docs/language/standard-library/modules/simulation/scenario/function/binding/) — Create a binding selector wrapper.
- [edge](/docs/language/standard-library/modules/simulation/scenario/function/edge/) — Create an edge selector wrapper.
- [entity](/docs/language/standard-library/modules/simulation/scenario/function/entity/) — Create an entity selector wrapper.
- [every](/docs/language/standard-library/modules/simulation/scenario/function/every/) — Create a trigger that fires once per calls matching hits.
- [once](/docs/language/standard-library/modules/simulation/scenario/function/once/) — Create a trigger that fires once.
- [probability](/docs/language/standard-library/modules/simulation/scenario/function/probability/) — Create a trigger that fires with probability in parts per million.
- [when](/docs/language/standard-library/modules/simulation/scenario/function/when/) — Create a trigger that fires when predicate accepts the attempt.