The official Twitter account for Pokémon GO has announced that Trainer Battles has gone live for all players level 10 and up. This is the lowest the limit reaches.
Attention: Level 10 will be the lowest level of Trainers that can access this feature. For Trainers levels 10 and below, we encourage you to keep catching Pokémon and exploring the world of Pokémon GO! We have no doubt that you’ll be a level 10 Trainer in no time!
— Pokémon GO is ready to #GOBattle❗ (@PokemonGoApp) December 13, 2018
Prizes such as 500 Stardust and a Sinnoh Stone can be earnt for participating in battles (even if you lose!). THis happens for the first three battles you do a day.
You can also now battle the Team Leaders in each league, with them going for a type-themed team. Blanche mostly uses Water and Ice types (the latter to parallel Articuno, the Pokémon mascot for the Mystic team which is in her team in the Master League), Candela uses Fire types (including Moltres in the Master League), and Spark Electric types (including Zapdos).
You can also now teach a second Charge attack to Pokémon. The higher amount of distance required to earn a Candy via Buddy walking for the Pokémon, the higher the cost. This ranges from 10,000 Stardust and 25 Candy for 1 km Pokémon, plus Baby Pokémon and Kanto Starters, all the way up to a whopping 100,000 Stardust and 100 Candy (for 20 km buddies; i.e. Legendaries).
Some bugs have been encountered. An ‘Error 2’ message appears at times when trying to accept a challenge. We suggest trying to send a challenge again, or alternatively have the other player issue the challenge next time. Meanwhile, battles can lag out, or multiple Charge moves occur for one player before the other can fully charge one regardless of tap speed. This may be tied to issues within the game tracking such moves being used when a Pokémon is Switched or Fainted and then Switched out.
Have you tried out any Trainer Battles yet?