This formulation is from Samo Burja as part of his Great Founder Theory:

Great Founder Theory - Samo Burja

A live player is a person or a tightly coordinated group of people that is able to do things they have not done before. A dead player is a person or a group of people that is working off a script, incapable of doing new things.

Important aspects are:

Examples of live players

Examples of dead players