For Honor patch 1.08 out later today, implements quitting penalty

Although that won't be activated just yet.

For Honor's promised quitting penalty feature will be implemented in a couple
 of hours—although it won't be turned on just yet. The system will inflict a ten-minute matchmaking penalty upon players who quit the game mid-match (although there will be a 30-second grace window after each game begins). The penalty will affect all group members, if the leader does a runner, although the system as a whole will only be present in games played through matchmaking.

There's no indication as to when the penalty system will be switched on, so until it is, feel free to quit anytime you like. Actually, don't. That's kind of a jerk move if you're playing in a team.

Patch 1.08, as detailed by Ubisoft here, also makes a few tweaks to several classes, while fixing a few bugs that are unfortunately not quite funny enough to include here. Check the preceding link for the full list of changes, but I'll stick the bit about the quitting penalty below.

"Developer comments: We are now able to activate the Quit Penalty feature during matches. When activated, players leaving the session will receive a penalty. This will reduce the amount of Rage Quitting during matches and improve the overall quality of match experience. The feature is included in this TU but will only be activated at a later date."

  • The player will receive a warning message about the penalty before quitting the match
  • If the player proceeds to Quit (via the in game menu or Alt+F4) they will receive a 10 minute matchmaking penalty
  • This penalty is also applicable to all group members if their leader leaves
  • There is a 30 second grace window (duration is adjustable) at match start to account for incomplete groups/matchmaking issues
  • The quit penalty only applies to games played through matchmaking