I just started a home game, introducing 4 new people to the hobby via S&W Core. While I was helping the other players with their characters, one of them decided that their Magic User would be an Elf, dismantling race-as-class just like that I didn't notice until we'd started playing, so I just rolled with it.
I'm guessing I should hit him with a level limit (8? 10?). I'm also considering a different XP progression, modifying the BECMI Elf Magic User in Threshold 10 to fit S&W.
How would you handle the situation?