The Player Discovery token is one of the three tokens that move on the Discovery Track. It tracks the collective progress of the players towards discovering how to avert or otherwise deal with the awakening of the Elder One.
Discovery Track
The Discovery Track tracks the progress of the players and the enemy during the game, and also controls when a new Act begins.
At the start of the game, the Player Discovery token and the Enemy Discovery token are placed at the first space on the Discovery Track, and the Elder One Discovery token is placed on either space 8, 12 or 16 on the track depending on whether players want to play a short, medium or long game. The chosen starting point for the Elder One Discovery token counts as the end of the Discovery Track. (The Elder One Discovery token can advance towards lower numbers on the track at some points in the game, but that doesn't change where the end of the track is.)
The players win the game by reaching the end of the Discovery Track without losing the game before that. They lose the game if the Enemy Discovery token reaches the end of the Discovery Track before the players do, or if the Elder One is awakened and completes its objective.
The first time the Player Discovery token or Enemy Discovery token reaches position 4, 8 or 12, it triggers an End of Act, and then a new Act begins. Note: when playing a shorter game by choosing a lower starting position than 16 for the Elder One Discovery token, the game will end before all the Acts of the full game have started.
Note: while the normal way of advancing the tokens on the Discovery Track occurs as part of the Enemy Phase.