[Gateway103]

IIRC, all commanders (and possibly units too, never bothered to check) gain 1 XP per turn just by doing anything not XP related (i.e. not fighting, or entering war academy, and not enhanced by items). So A researcher would gain 1 XP per turn, whether she researches or not.

For example, in my long SP testing game as Atlantis, which finally ended on turn 221, all mages in my capitals were ofLevel 3 & 4, whom I know were hired in the early days to fuel my research. And since I was the only water nation, these mages never seemed battle at all (sitting home and hit books). So this seems to collaborate my memory that commanders gain 1 XP per turn at minimum, as some of these researchs would get 200+ XPs (level 4), while the rest were level 3, as observed.

Just an observation.

-Gateway103