Vampires will not enter a temple that has a priest in residence.

Priests tending an altar should repair the walls and doors of their temples if they are damaged, like shopkeepers do. (In NetHack 3.7, peaceful monsters avoid digging temple walls, but the temple can still be damaged by other monsters or the player.)

Temples are always lit up; never dark.

Revamp the Oracle: move it lower in the dungeon, add level variants that make it look like a real temple instead of a small room inside a big room, and make the Oracle act as a real priestess, providing consultations along with regular priest services.

Aligned priests in a coaligned temple attempt to pick up corpses lying around and sacrifice them.

Put an attended temple to Moloch in the Orc Temple Mines’ End, and guarantee generation of the Orc Temple if Minetown has already been generated and is Orcish Town, so that an aligned priest always exists (unless the player’s unlucky enough to generate a non-Orc Temple Mines’ End prior to generating Minetown, and then visits Minetown and gets Orcish Town).

Instead of a human priest of Moloch, it might be possible to have one of the orc shamans generate with an epri struct attached, so it tends the altar like a normal priest.

Priests attending a temple altar can magically fix their temple’s walls periodically like shopkeepers can.

If you enter the temple of a god who is angry at you, all monsters on the level become awakened and aggravated. This should print a more menacing message than the standard “forbidding feeling” one. (Note that a proper implementation of this requires that gods’ anger levels be tracked separately for each god.)

One Gehennom “special room” should be an active temple with a peaceful priest of Moloch.

Soul selling: when you summon a demon lord, there is some opportunity for you to sell your soul to them in exchange for a wish.

• Selling your soul both angers your god and suppresses all interaction with them.
• You may be able to recover your soul by killing the demon lord; for balance the demon lord should go far away when you sell your soul, though not out of the game.
• Alternatively, unless you wish for nothing (which makes the demon lord vanish forever), the demon lord will immediately become hostile, making it an unlikely tactic in the early game.
• Entering a temple without your soul will immediately anger the priest.
• Your quest leader won’t let you go on the quest while you are soulless.

Sanctuary in coaligned temples is granted only if your prayer timeout is nonzero.

Holy water fountains in temples (would require balancing though).