Can I level quickly by exploiting level drain and restoration?

Question

Suppose an archmage has an apprentice, a level 1 wizard who he wants to train quickly. He attempts the following:

1. 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.
2. 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.
3. 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.
4. 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?

Answer 1

restoring the creature to the highest level it had previously attained

^{(from greater restoration)}

The creature had never attained any level above 3rd. When greater restoration is cast on it, it is restored... to 3rd level. Which it already has. I.e. nothing happens.

Restoration, rather than greater restoration, doesn’t mention anything about “previously attained,” though. But, even rules as written, the entire restoration line uses, unsurprisingly, the word “restore.” That doesn’t have a game-definition, so we use the English definition, and you cannot restore that which was never there in the first place. This never works.

Answer 2

No

Ignoring the cheese (which I shall touch on briefly) there is one key problem with this scenario.

Step 1: "The archmage fights moderately powerful monsters with ease" - if the apprentice is not participating in the battle or contributing significantly then the GM will not award them the bonus. This one is a bit of a judgement call though, not necessarily a fatal flaw. (If I were going to try this on then I would give the apprentice a wand of fireballs, cloak of the bat and dust of disappearance, locate a band of low level monsters and tell him to fly over and fireball them solo - that way he gets all the XP. I still have not met a GM who would buy it though.)

Step 2: Brutal though it is, the important thing here is that the apprentice must not just gain negative levels, he must fail his Fortitude save and actually lose levels after 24 hours. No rules issues, but the important thing is that the apprentice who was level 3 is now level 1. Otherwise he is still a level 3 character with a nasty disadvantage who requires more and more XP for each further level.

Step 3: Rinse and repeat steps 1 and 2 - no problems from a rules perspective (except for the ongoing judgement call on the validity of step 1).

Step 4: Here is where the wheels fall off this recipe. Restoration, Greater, states (emphasis mine):

This effect also reverses level drains by a force or creature, restoring the creature to the highest level it had previously attained.

So, this will restore the hapless apprentice to level 3, as this is the highest level he had previously attained. It does not matter how many times he has previously attained level 3, he cannot be restored to a level greater than 3 by RAW.