In my game group there is a player who plays a warlock-druid (1-1). He started as a warlock. He realized he was playing as an NG, but he took CN for the restrictions regarding the alignment of his first class. The manual says that a warlock must be either chaotic or evil. A Neutral Good does not respect either of the two cases and we wondered what could happen, considering that the ex-warlock does not exist and the choice of alignment is not free
In the Complete Arcane there is written:
Alignment: Warlocks are often chaotic or evil (and more than a few are both). The powers they serve can be cruel, capricious, and wild, unbound by conventional views of right and wrong. However, even warlocks who derive their powers from the most sinister of patrons have been known to turn the black powers at their command against evil. A good-aligned warlock is a grim and fearsome enemy of evil. All too familiar with the darkness lurking in his heart, he gazes unflinchingly on the evil in others and battles the foulest of foes without fear.
And at page 7 we can read:
Warlocks have the following game statistics.
[...]
Alignment: any evil or any chaotic
However, the manual does not refer to ex-warlocks for changed alignment or warlocks that no longer respect the binding alignment and change it.
What happens in these cases?