The leader of the army participates in battles quite intimately, strolling about the battlefield and bringing their skills and abilities in there while also providing themselves as a high value target. This is mostly for strategy games.
The first video game about Leader participation was released on November 11, 1995.
* Elites - not enforceable in cases where the leader is actually equal or weaker than those around them.
In multiplayer games this makes assassination literally possible.