A cleaner way to say it is “capture the flag” or just “flag” if you mean the Roblox game/object. Roblox’s own docs use “Flag” for the game object and describe it in the context of “capture the flag” style games.

Better phrasing

  • Capture the flag.
  • Flag game.
  • Flag object.
  • Team flag, if you mean the item your team protects.
  • Enemy flag, if you mean the other team’s flag.

In a sentence

  • “Let’s play capture the flag on Roblox.”
  • “I grabbed the enemy flag.”
  • “That game uses a flag object for the match.”

Quick note

If you meant “flag” as in reporting a player or post, a clearer phrase is “report” or “submit a report” rather than “flag.”