Action is a more formal term for any kind of wager. A bettor who has action on a particular game has at least one bet tied to that game. Action is often referenced in online sportsbook rules, where certain events or occurrences may create no action.

If any selection in any leg is a non-runner or otherwise void under the Sportsbook Rules (e.g. an abandoned match) then all bets on that individual leg will be void and the parlay bet shall be adjusted accordingly. For example a treble including one void leg will become a double.