Excalibur in Avalon: rules, card flips and examples

Excalibur changes one submitted mission card: Success becomes Fail, or Fail becomes Success. It does not change a player's role or their vote to approve the team.
Rules
- After selecting a team and before the approval vote, the leader gives the sword to a team member other than themselves. Everyone can see who holds it.
- After mission cards have been submitted, the holder can flip another team member's card or skip using the sword. The interface does not allow the holder to target themselves or anyone outside the mission.
- A new holder is chosen for each proposed team. The final mission result uses the cards after the flip and the mission's required number of Fails.
Important limits
Who sees the flipped card? The use and target are public. During the game, the holder and target know the affected card's result; other players do not receive that private value.
Does Excalibur guarantee success? No: you pick a player before learning their card. A good player's Success can become Fail, and removing one Fail may leave enough Fails to lose the mission.
Practical situations
- On a mission needing one Fail, there is exactly one Fail. Flipping that card to Success saves the mission; flipping a different player's Success adds a second Fail.
- The fourth mission with 7–10 players needs two Fails. If two were submitted and one is flipped to Success, only one remains and the mission succeeds.