One In The Quiver is a minigame where every player starts with a bow and one arrow. You need to be the last one standing. To kill the other players, shoot your arrow at them. If they get hit by the arrow they will instantly die and you will gain a new arrow. If you miss you'll have to kill them with your hands. Every player has two lives.
Every OITQ server can get up to 20 player slots but only 8 players at a time can play the minigame. Tap the signs at the spawn to join the queu. Once you are in the queu with the next 8 players you'll get teleported to the arena where you'll be able to play.