Suppose an archmage has an apprentice, a level 1 wizard who he wants to train quickly. He attempts the following:
- He goes adventuring with the apprentice. The archmage fights moderately powerful monsters with ease, and within a day the apprentice has reached wizard level 3.
- The archmage hires a vampire to strike the apprentice with his energy drain attack, causing him to acquire two negative levels, which ultimately cause him to lose two levels. He is reduced to wizard level 1 again.
- The archmage repeats the first two steps nine times, so that the apprentice has gained and lost two levels ten times, twenty levels in total.
- The archmage hires a cleric to cast greater restoration on the apprentice. He immediately regains all twenty of his lost wizard levels, and is now a 21st level wizard.
Now, no reasonable DM would allow such cheese. But, rules as written, does this process work?
:-)
\$\endgroup\$ – Hey I Can Chan Jun 9 '18 at 14:58