At the end of every turn, Pandaren give a Harmony token to each opponent whose Active Race they did not attack this turn (including the first turn of the game, to players who do not own any Race yet).
A player with a Harmony token must pay 2 Victory Coins to the Pandaren before attacking them (attempting to conquer their regions or forcing the removal of a Race token from their territory by any means).
These 2 Victory Coins are only paid once, even if the opponent attacks several Pandaren Regions. Each Harmony token is retrieved by Pandaren at the beginning of each of their turns.