2,855. "A Nazir Except for..."

Hilchos Nezirus 1:12

Similarly, if a tipsy person was given a cup that would make him completely drunk and he declared himself to be a nazir from it, he is only prohibited that cup and is not rendered a nazir. This is because his intention was only not to become entirely intoxicated. If he was as drunk as Lot, then his words are inconsequential and he’s not responsible for his sins because when one is as drunk as Lot was, he is not liable.

Hilchos Nezirus 1:13

If a person declares himself a nazir on the condition that he can drink wine, become unclean through corpse impurity or cut his hair, he is a complete nazir and is prohibited all of these things. This is because he made a condition that was contrary to what’s written in the Torah; if a person makes a condition that contradicts what’s written in the Torah, the condition is invalid.