Angering peaceful monsters by casting an innocuous spell like light is very annoying, so split the spell up into a “light area” spell, which does not damage anything unless it’s a highly light-sensitive monster like a gremlin, and a “light blast” or “flash” attack spell, which may or may not light the area permanently and is designed to blind monsters.
If you approach a demon lord with a low amount of gold, they automatically become hostile.
When you kill an auton, the auton that upgrades itself elsewhere on the map becomes hostile to you if it wasn’t already.
Chatting to intelligent monsters gives you the opportunity to mock them, which will anger them without incurring an alignment penalty.
When you anger a peaceful monster capable of speech, it may call for help. Other peaceful monsters of the same monster class within a fairly large radius may wake up and, if awake, will become angered.
New exclamations for peaceful monsters getting mad at the player when they attack another peaceful: “Hey!” “Stop that!” “Get [him/her]!” “Oy!” “Jerk!” “Try me instead!” If hallucinating, add “Dude! Not cool!” to this list.
Stealing gloves (also possibly named “rogues gloves” or “gauntlets of thievery”). 0 base AC, and Rogues begin the game wearing a pair. When you hit a monster barehanded while wearing them, you deal no damage (and don’t train bare handed combat skill) but you get a Dex-versus-monster-AC chance of stealing a random non-equipped item or some gold out of their inventory. You can also attack a peaceful monster with them to attempt to steal something; in addition to the Dex-vs-AC roll, this requires passing both another Dex check and a Cha check for them not to notice. If the Dex check fails, you don’t steal anything successfully; if the Cha check fails, they notice (waking up if asleep) and get mad. If the stolen item is currently equipped, there’s no Cha check; the monster just gets alerted and angry.
If a peaceful unicorn sees you wielding or applying a unicorn horn, it gets angry.
Telling a vault guard you are Croesus or an alias might fail, depending on your Charisma. If it fails, the guard becomes hostile.
If you kill a grown-up form of a monster, all equal or lesser forms of it that see it die turn hostile even if they were formerly peaceful and the monster you killed was hostile.
Priests object to you locking the door of their temple, and will unlock it if you try. If they cannot for some reason, they get angry.
If ents exist, chopping down a tree angers any ents on the level.
If you attack a peaceful monster, other peaceful monsters that saw the act but grudge the first monster will not be angered.
Shopkeepers track your petty thefts, and automatically anger if you steal a valuable single item or 50% of their stock or items totaling more than 1000 zorkmids.
If you attack a peaceful monster in sight of your quest guardians and leader, they give you a warning rather than instantly becoming angered.
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.
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).
