Getting crowned as a lawful character should unlock the ability to dip for Excalibur if you are currently unable to, or raise the odds for successfully dipping to what Knights get.

Lawful-aligned characters should feel guilty and incur an alignment record penalty in addition to the normal Luck penalty when they cheat in Sokoban.

Allow all lawful devils (or a random set of lawful devils) to accept a bribe, not just Asmodeus and Baalzebub. They will not vanish completely, but they will turn peaceful.

If you are polymorphed into a nymph and are lawful, you suffer an alignment penalty for stealing items from other monsters.

If a system is implemented that tracks the amount of booze you have drunk throughout the game, lawful gods start to penalize the player for drinking too much after a while.

Lawfuls get an alignment penalty for writing graffiti with a marker, even if it’s Elbereth or something else useful.