Yer a Harry, Wizard!

In Apprenticeship you were a fairly ordinary being from your world of choice when you were presented with the opportunity to apprentice to a powerful wizard from another dimension. Why did you believe him? Why did you accept? I dunno, man, that's your backstory, not mine.

Anyway, now you and your fellow apprentices spend a good part of your time in the wizard's pocket dimension (The Tower) cleaning up alchemical spills, washing soiled robes, cooking the old man's dinner, and acting as a living mana battery. Occasionally you're taught some magic, if the old man feels like it.

Even more occasionally you're sent on a perilous adventure of dubious merit, usually to acquire some strange artifact or obscure magical reagent somewhere in the multiverse.

Many of these adventures will be plagiarized inspired by old published modules from my collection of RPG material so don't be too surprised to find yourself looking for magical leaches in Saltmarsh or trying to collect dhole tears in the Mountains of Madness.