If you bribe a demon lord for safe passage using Demonbane, they melt it down in front of you while laughing maniacally.

Bribeable humans may refuse an initial sum of money you throw at them, with 50% chance. Usually they say “It would take [some number of] zorkmids for me to abandon my duty!” which you can then provide if you wish.

Restructure Gehennom to be very short, containing the Valley, the three Wizard’s Tower floors, and a “nexus” floor at the bottom, containing the vibrating square and four magic portals, each leading to a randomly selected demon lair.

You can only enter each lair once: you must decide whether to attempt defeating the demon lord or not before leaving. The exit portal won’t work if invocation items are left behind. The demon lords are beefed up from vanilla, and are not bribeable since they’re not guarding access to the stairs to extort passage.

As incentive for defeating the demon lords, they apply debuffs on the ascension run, described in #3396.

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 approach a demon lord with a low amount of gold, they automatically become hostile.

If you bribe a demon lord with less than 1000 gold pieces, a Wizard-style periodic timer is started, except that every time the timer triggers random demons will be spawned around you. The demon lord itself may return, hostile this time.

Demon lords that accept a bribe don’t actually go anywhere. They get out of the way to the stairs if they were previously in the way, but otherwise they have their movement points set to 0 and cease warping for as long as they are peaceful.

Asmodeus and Baalzebub demand gold proportional to their difficulty or monster level, not the player’s wallet. Possibly, if the player does not pay, they remain on the downstairs and will not move until the player has paid, which allows the player to return with the requisite amount of gold (and may charge interest for the time you spent keeping them waiting). However, they will get angry if you get below their lair in any way (possibly measured by testing your lowest level reached each time you enter the lair).