Many abilities and other effects modify the amount of damage an attack deals (through boosting, deboosting, adding additional damage dice, or other means). These damage dice may also have damage types associated with them that may incur additional effects. Damage may have multiple types. If no type is specified, the damage is considered to be "mundane".
The total set of all damage dice that would be rolled (including types) is referred to as standard damage. If an ability says it "deals standard damage" it means deals damage, considering all relevant modifiers in the process. Some abilities also deal critical damage. In these cases, roll each damage die twice (after applying all boosts and deboosts) and deal that much damage instead. This doesn't automatically double static increases or decreases to the amount of damage dealt, unless explicitly stated (such as by Slay).Core:Damage Rules