The entity which the player represents in the game world. This can be a single character (Snake in Metal Gear, Mario in Super Mario), a collection of characters (a football team, an inseparable RPG party) or a bundle of interactive abilities able to affect the world.
An avatar, or player character, is a manifestation of player role, but a role can exist independently; this allows us to separate the concept of the player’s existence within the game world from that of a narrative’s main character.
“In real terms, you are not the mayor of Sim City. It’s a convenient shorthand, but the player role is actually that of an entire city’s worth of officials working in tandem to run dozens of services.”