In Battle, players will face off in a Hunger Games-style death match until one victor remains. The matches will have resources around the arena that will be decided randomly. If you don’t end up being the victor, don’t worry, you can spectate the gameplay by flying around as a bat. 

– Jaime Limon, Senior Product Marketing Manager for Minecraft

Battle and three new maps will come absolutely free in an update as long as you have a console.