A call or verbal (US) is a verbal means of indicating a mechanical effect in a larp. They are typically used in live-combat larps.
Simple calls can be used to indicate combat damage ("two" or "double", "triple", "twenty" etc). Simple effects are typically phrased as imperatives or descriptions e.g. "sleep", "paralyse", "death". Some rulesets, such as Accelerant, have sophisticated call grammars allowing effects to be described by effect and type to allow for multiple origins or types of resistance.