If you are a gnome and encounter a monster wearing stomping boots, they can stomp on you to instantly kill you, just like the hero is able to do to small monsters while wearing those boots.

Change Werebane’s base item to a ring of protection from shape changers. Confer the same sort of properties as it currently has now: while wearing the ring, you will deal double damage to and possibly even sear werecreatures even if your weapon is not silver, and possibly even instakill them on a critical hit.

Add two dice objects: a magic die and a plastic die. Both appear as “game die” when unidentified, are made of plastic, and weigh 2. Dice can be rolled by applying them or throwing them (upward or downward).

Magic dice are chargeable. They start out with 3-5 charges; uncursed charging adds 1 and blessed adds d3, up to a maximum of 7. The die can only be recharged twice.

Rolling either type of die produces a message “The die spins around and lands on [number].” Plastic dice and non-cursed magic dice use a d20 with even probability; cursed magic dice bias the result towards lower numbers such that the probability of each possible roll is proportional to 20 minus that roll (so there is a 19/170 chance of a 1, an 18/170 chance of a 2, etc.)

The effects are:

One possible alteration is to do away with both the instadeath and the wish, because it’s been pointed out that nearly all the negative effects are recoverable. The player has an incentive to hold off on rolling the die until they have the wherewithal to recover from most of the negative effects, and then roll it as much as possible in hopes of getting a wish, while suffering few permanent issues. Giving the die a chance to just unavoidably end the game to compensate for wishing abuse may be unsatisfying.

Alternate god smitings (to go alongside striking with lightning): chaotic gods or Moloch try to create lava around and underneath you, and neutral gods blast you in a magical explosion that instakills you if not magic resistant, curses all your items, strips any charges from charged items and disenchants gear to something highly negative.

The Heart of Ahriman should do instakill when it is slung and hits a monster with a head who is not wearing a hard helmet. To encourage this, Barbarians should get Basic skill in sling.

To compensate for inevitable cheap deaths, any monsters that are too important to cheaply instakill via this method need to be given hard helms of some sort.

Any monster that is somehow forced to stand on a scroll of scare monster while being affected by it is immediately scared to death.

An artifact mask Mask of Many Faces, neutrally aligned. When invoked, you are prompted to target an adjacent creature. If that creature fails a monster magic resistance check, or a d(its maxHP) roll is lower than its current HP, it is instantly killed, dropping its possessions but no corpse or other special drops, and the mask changes to that creature’s form.

Subsequently donning the mask, or having it worn when invoking it, merges it into your skin and polymorphs you into that monster’s form, starting a timer (not the usual polymorph timer) after which the mask will turn blank and the polymorph ends. Lower level monsters than the player will produce a longer timer, and higher level monsters and uniques will produce a shorter timer. You can also invoke it again while wearing it to end the polymorph early.

Teleporting no longer checks to see if there is a monster present on the destination tile. Teleporting into a monster’s space has a chance of telefragging and instakilling it. (Though for fairness this should also happen to the player if a monster randomly teleports onto their space.)

The ring of warning, and only that, should indicate the exact amount of turns you have left to live when afflicted by a timed instadeath such as sliming, stoning, or strangulation. (And drowning and other forms of suffocation in variants that have that.) This feedback is conveyed by the ring vibrating that number of times, e.g. “Your [ring] vibrates twice.” Possibly it should only happen when the amount of turns to live is low because it doesn’t make that much sense for it to vibrate 20 times in one turn and have the hero count that accurately.

Don’t allow any single source of HP loss to kill you if you had full HP before the loss, unless your maximum HP is less than 10. (It would presumably leave you at 1 HP).

Any rock mole (including you, if you are polymorphed into one) that eats a wand of death dies instantly.

Non-fire-resistant creatures have a very small chance of spontaneously combusting in Gehennom.

Outside the Plane of Air (where there is no gravity), stepping onto air terrain automatically makes you fall to your death unless you are levitating or flying. (Or possibly you merely fall to a lower level, taking a fair amount of damage, or you have so far to fall that it takes a couple turns to hit the bottom, in which you have a couple turns to take some action to save yourself, by levitating or flying or whatever). However, you are prompted to confirm stepping out into the open air if it isn’t safe to do so.

Items dropped into open air either end up randomly placed on a lower level if there’s a sensible lower level to place them on, or vanish forever (though in that case an exception needs to be made for the unique items).

If falling into air is an instadeath, life saving acts the same as if you die in lava; it puts you on a safe location (“You find yourself back on solid land again”).

Air can use the W_NONDIGGABLE flag, or possibly one of the other struct rm flag bits, to represent a wind barrier, which the level designer can use to make a region of air impassible. Attempting to move onto such a space produces a message like “A strong gust blows you back!” and makes you lose the turn.

One of the greatest problems with air terrain is what ASCII character to display it as; existing implementations use just regular space (which is what it displays as on the Plane of Air), but this is easily mistaken for stone, which can lead to players unexpectedly falling to their death if there is no safeguard against wandering off a cliff, and would present a problem if there were ever a air/stone boundary, which would be invisible. Other suggestions include: space, but highlighted with the terminal’s black color ( ), black pound sign (#), black tilde (~), black right brace (}), or even just gray counterparts of these. All of these have various downsides; for instance, it must be expected that they will render as dark blue for some players who have use_darkgray turned off.

If you are mostly surrounded by puddings, they will merge together all at once and engulf you. This is a delayed instadeath in several distinct stages:

1. The puddings tower over you and merge together, preventing escape. You are engulfed, but you can still do things like attack or zap a wand of opening.
2. One or two turns later, your arms and legs are grabbed. You can no longer use most items but may still be able to cast spells and read scrolls.
3. The pudding spreads over the rest of your body. You can’t speak or do things that require speaking, though prayer is still possible.
4. The pudding is forced down your throat, dissolving you from the inside. This either kills you instantly or gives you a few more turns to live if you have magical breathing.

Amulet of drain resistance, which also gives immunity to death magic. Useful if monsters casting drain life are implemented.

Trappers’ and lurkers’ above digestion happens much more quickly than purple worms, on a shorter timer. As it stands, most digestion attacks aren’t very threatening as an instadeath because the player almost always has time to kill the digester.

For that matter, all digestion attacks should probably be accelerated somewhat, even those of purple worms.

Instakill effects deal a large amount of HP damage rather than instakilling, and give an appropriate message when something survives them.

Stomping boots. While wearing these, you may instakill and move into the square of all small monsters in the a, s, and x classes.

Instead of instakilling, death rays cause a delayed instadeath that require consumables or prayer to fix. Touch of death should also probably fall under this.

Hallucination should prevent against all death magic, including death rays, using the “near death experience” logic. Not just the touch of death.

Make death magic resistable by an amulet or ring. Possible names and corresponding exact effects vary:

• “life protection” (bad name, life saving is very similar)
• “unliving” (makes you not count as living and life saving won’t work)
• “undeath” (actively makes you count as undead, you are vulnerable to turn undead effects and lawful gods may be annoyed at you)
• “versus death magic”

Wands of digging kill any monster made of earth instantly.

The Master Assassin has an instakill attack (though not unpreventable; the player should be able to prepare and protect themselves some way).

Attempts to analyze good instadeaths versus bad instadeaths (loosely defined as ones that are instant hard-to-avoid deaths that aren’t really similar to running out of HP):

• Poison, digestion, lava, death magic, and drawbridge instadeaths can easily be converted into HP damage of max(damage dice roll, substantial % of your max HP).
• Drowning and choking would be well-suited to a breath system, where it becomes a delayed instadeath. Especially so if you can stop the clock by putting on an amulet of magical breathing or praying.
• Intelligence drain and level drain generally can’t happen without the player being given ample time to escape, so they are fine.
• Starvation could be changed to HP loss, but you usually just die from side effects of fainting anyway.
• Instadeaths that almost always have to be intentionally caused by the player (self-genocide, divine wrath etc) are generally fine as-is.
• Instakilling artifacts are problematic, because there is currently no recourse except for the amulet of life saving.
• Eating or digesting the Riders should not instakill without warning, because it is now unexpectedly a bad idea to eat a reviving corpse, whereas it had been a good idea in the rest of the game.
• Good instadeaths generally use unusual resources to fix, or hit the player’s reserves in an unexpected way, and allow the player a chance to get out or stop it before dying.

Getting lifesaved gives you experience points (because it’s a near-death experience). So should having a out-of-body experience from getting hit with death magic while hallucinating.

Remove instances of “bad RNG” contributing to forms of instadeath or a disproportionate bad effect for a RNG decision made mostly or completely independently of the player’s decisions, because they just add randomness or variance to the outcome of the game:

• Poison instadeath
• GWTWOD
• Chameleons turning into out-of-difficulty monsters the player can’t handle

Split up the effects of magic resistance, as it is too extensive. It protects against magical force, death magic, teleportation, polymorph, etc.

• Death resistance conferred by a helm, an amulet, maaaaaybe as an intrinsic gained through crowning