From the introduction:
Sueperpowered is a TTRPG about Mary Sues, and embracing the tropes associated with them unironically. It encourages being self-indulgent and shameless, and having fun over all else.
One player acts as the Suepervisor, the game's facilitator. All other players act as the Sues themselves.
Only six-sided dice, a means to record information, and a willingness to approach the concept of Mary Sues with sincerity, are required to play Sueperpowered.