Ice devils have a “hellfrost” attack that can damage you even when you have cold resistance (though possibly not if you have extrinsic cold resistance).

Fire Brand gives you extreme vulnerability to cold damage, making you take quadruple damage from it. If you have cold resistance, this only reduces it to triple damage.

Frost Brand works the same way with fire and fire resistance.

Make it impossible to have fire and cold resistance intrinsically at the same time. If you eat a corpse that gains you one, you lose the other. Things like crowning that give you both now do not give either (unless perhaps you have neither, in which case you get a random one).

Extrinsic fire and cold resistance are not affected. This makes it valuable to have those extrinsics from a ring, underused colors of dragon armor, or an artifact.

All polymorphable monsters that currently resist both fire and cold must have one of those resistances taken away; otherwise you could have both at once by polymorphing into them.

Tortles who have cold resistance don’t stumble when walking on ice, because their feet have claws to give them a good grip.

Artifact ring that provides a cocktail of basic resistances all at once (fire, cold, shock, poison, maybe sleep, maybe acid). This is interesting primarily because it is very useful early in the game and then becomes progressively less useful later on as the hero gets intrinsic resistances.

Could be named “The Ring of Everything Resistance” or “The Chromatic Ring”.

New type of terrain, “fire terrain”, a square that is on fire. It displays as an orange period. (If this will be too nasty to people who play with color off, the glyph should perhaps be changed.)

• Fire terrain has a certain amount of burning wood material on it.
• Standing next to or on fire terrain grants cold resistance, but standing on top of fire terrain has the same effect as a fire trap whenever you end your turn on it.
• The fire eventually burns out and reverts to normal floor, the duration determined by the total weight of the burning objects.
• Killing a wood golem with fire or burning more than a certain weight of objects on a square creates fire terrain on that space.
• Throwing burnables onto a fire trap may make them spontaneously combust and produce fire terrain.
• Fire terrain can be used to cook corpses.
• You can create fire terrain by applying a lit candle to a space with burnables on it
• You can also create it by applying a tinderbox to a space, which is a chargeable non-magical tool. Archeologists and Rangers start with one.
• Fires provide a light source of radius 3, but cannot be moved.
• Monster AI will not travel over fire if the monster is not resistant.

Water demons should resist cold instead of (or in addition to) fire.

Revamp Gehennom by making its main branch substantially shorter, a “hub” branch containing stairs or portals to a bunch of sub-branches containing demon lords’ lairs. Most of the lairs are optional, but at least some of them are required in order to enter the Sanctum. Each demon lord that you don’t kill, however, incurs a unique, harsh effect or debuff on you once you have the Amulet. Suggested ones include:

• The mysterious force, as it exists in vanilla.
• When you try to ascend the stairs, they vanish and several illusory copies of stairs appear across the level, along with one real one which you have to find.
• Walls extrude from existing walls around the hero in random directions, never entirely closing off, via a cellular automaton that looks for walls with a 3x2 area of walkable spaces in front of them, with the space directly in front a regular floor space - the effect of this given enough iterations turns the terrain around you into a maze.
• Generic damage over time, not severe but enough to provide a headwind. Or partial or total disabling of natural regeneration.
• Asmodeus: Some damaging cold effect that happens periodically, or your cold resistance is nullified and replaced with a vulnerability to cold effects.
• Baalzebub: Something to do with insects, either periodic summon insects from nowhere or stronger/more frequent insects
• Juiblex: You may randomly become ill, or have your regeneration dampened or something
• Geryon: Hordes of buffed q generate and rampage periodically.

Woolen shirt, shirt-slot armor which gives zero AC but cold resistance.

Intrinsic cold resistance only halves damage from Asmodeus’ cold attack. Only extrinsic cold resistance protects against it fully (or cuts it to 1/4?).

The Staff of Necromancy: an artifact quarterstaff that deals double damage to non-drain-resistant creatures (but doesn’t life-drain them as the Staff of Aesculapius does), grants cold resistance and curse resistance when wielded, and can be invoked to raise one vertebrate corpse on your square as a tame skeleton.

Additional temporary effects accompany drinking a potion of booze. The effects wear off when the confusion does (so if you extend it by, say, drinking a potion of confusion, the effects are prolonged). There is consensus that there should be both positive and negative effects; all of the following have been proposed:

• A damage bonus, or even double damage
• Temporary HP
• An accuracy penalty (or a Dexterity penalty)
• Slight reduction of speed
• Temporary cold resistance (debatable; if possible it should probably make you not feel cold attacks but still take regular damage from them)
• Attacking an enemy makes you automatically keep fighting it until one of you is dead
• Monsters are treated as having higher charisma (currently no monsters are treated as having charisma at all, but this could also hurt or nullify your ability to refuse a foocubus removing your clothes)
• You may pass out when the confusion ends, and end up with a hangover when you wake up. (Not described what the effects of a hangover would be). You may also find yourself suddenly on a different level when you wake up.
• You are protected from gaze attacks due to not being able to focus enough to meet someone’s gaze.
• If you’re a dwarf, the effects get magnified
• If there is any such thing as a player-is-scared effect, it is canceled when you drink the booze and blocked while you’re under the influence. This goes for however long the confusion persists, so you can extend it by drinking potions of confusion if you want.
• Any AC from your armor is nullified (this would also contribute to monk “drunken boxing” proposals, since monks don’t usually have as much armor AC)