With the release of the latest v1.04 update; "AR" (or "ArchRivals") was introduced, a dedicated 1-versus-1 game mode. (As well as a new, re-vamped ELO-based ranking system. (Plus many other awesome things!))
It must be said that I have had few AR matches (at the time of posting) but, from the few that I have had/played, there are some alarming factors of the AR mode that require attention. There are some very good suggestions that were made in this thread:
However, I think it can be improved in another way. Very similar to the new Unreal Tournament "Showdown" game mode, but with some other tweaks/adjustments.
Make it (AR) "round-based". Any kill will result in both players being FORCED to respawn, creating a new "round". (It should go without saying that a new round must reset everything in the map.)
Make all weapons upon pick-up grant x% (x being debatable) of full ammo, and then NOT being able to be picked up again by the same player. However, the other player must still be able to pick up a weapon that the "other" player has picked up. (Once picked up, the respawn time of any weapon must be immediate!)(Then that person (the "other" player, as mentioned) will not be able to pick it up again.)(Basically, any weapon can only be picked up ONCE, by the players in an AR match, per round.) - I hope that makes sense :?
No ammo pick-ups must be available. If someone runs out of ammo with whatever weapon during a round, that's it. No more use of that weapon in that round.
A round must be time-limited. IMO, 2 minutes. If no kills are made, the round will be considered as null. (That said, if players only want to avoid each other, three consecutive "null rounds" will result in game end, with no victor.)
The MH and MA (Mega Health and Mega Armour) should be REMOVED, as well as the HR (HellRaiser (Redeemer)).
The +50 armour must respawn faster. (30s was suggested.)
Spawn players with 100 HP and 50 Armour.