From the announcement:
Once a month, selected stores can host a Sidekick Night, where veteran HeroClix or Dice Masters players will bring someone who is new to the game and interested in learning, as their Sidekick. They’ll play side-by-side against another player and their Sidekick, with the veteran players providing some advice and instruction. Players will be rewarded just for showing up*! At the end of 3 months, players and their Sidekicks who have attended at least 2 Sidekick Nights will be able to win limited edition HeroClix or Dice Masters prizes. There is no recommended entry fee for Sidekick Night.
*Stores will reward participation prize to each player the first time they show up to Sidekick Night in a Sidekick Season. On the 3rd Sidekick Night, players who have attended at least twice will be eligible for an entry into a random drawing for HeroClix or Dice Masters prizes.