Various effects for armor pieces based on their randomized description:

• Buckled boots and old gloves: cost (and sell for) twice as much in a shop.
• Hiking boots: prompt before walking into known pits or holes.
• Mud boots: autocurse when worn.
• Padded gloves and visored helmet: +1 to AC.
• Tattered cape: -1 to Charisma.
• Ornamental cope: +1 to Charisma.
• Opera cloak: some sort of bonus when using musical instruments.
• Plumed helmet: +1 to Charisma, -1 to Dexterity (or have these adjustments multiplied by its enchantment).

Remove the ability to accidentally enter y or n on a confirmation prompt when trying to use those keys to move; instead, have all y/n confirmation prompts require you to input capital Y or N.

In an effort to reduce the number of low-importance y/n confirmation prompts in the game, make applying a lock pick or key scan the hero’s inventory, the floor underneath them, and 8 surrounding spaces for doors or containers that the tool can be used on. If there is only one such thing, automatically use the tool on that thing without prompting. If there are multiple, either prompt for each one in sequence or offer a menu of things to use the tool on.

This has a problem in that heroes may end up accidentally locking doors they want to go through. The problem may not be that important, since they can just unlock it again. Another suggestion is to make the map symbol for a locked door different from an unlocked one.

Cleaver can be invoked to toggle its arc-attacking on and off. This should perhaps not set its invoke timeout, since it isn’t giving the player any particular benefit. However, it’s a bit problematic what the default setting should be; if it starts out in no-arc mode it will be hard for players to discover that it has an arc mode at all; if it starts out in arc mode players may hit a peaceful target in their first few attacks before remembering they need to manually toggle it.

Alternatively, just prompt the player for confirmation if the attack they are about to make is obviously going to hit any peaceful or tame monsters.

Remove the player’s Intelligence as a factor in determining the outcome of a foocubus interaction. Instead, use Intelligence (or possibly Wisdom) rather than Charisma as the determining factor in whether they are able to say no to having a piece of armor removed.

The chance of a foocubus getting a severe headache after an encounter is elevated if you refuse to pay it, underpay it, or have no gold with which to pay it. (Refusing to pay should probably not be random and automatic anymore, it should ask if you want to pay instead.)

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 try to go up or down stairs or enter a magic portal, and there is a pet that is still eating next to you, you are prompted to confirm changing levels. Also remove the “foo is still eating” message since it will then be covered in the prompt.

When standing on a (not known untrapped) container and using the search command, prompt the player to check for traps on the container. Search normally if they say no.

When the player is prompted to rename an object or a level that already has a name and submits an empty string, ask the player for confirmation to remove that name entirely: “Remove old name? [yn] (n)”

Allow configuration of a list of monsters that the player should be prompted to confirm fighting before automatically attacking by moving into them. Fighting with F bypasses this check.

Also, possibly add an option to make this behavior happen for any monster.

Option to make the confirmation letter “Y” instead of “y” so that you don’t accidentally hit people when moving in the “y” direction.

Attempting to wear armor while already wearing armor in that slot will prompt you to remove it.

You should be prompted to confirm before attacking a monster while standing on Elbereth.

Warn the player before they melee a monster with passive attacks.

If escaping a prompt would use up an item or charge, re-prompt at least once (or maybe have an option configuring how many times it re-prompts.)

Make the “Destroy old game? [yn]” prompt harder to destroy a game than simply hitting y. Probably ask “Are you sure?” and force the user to type out yes.

The game should ask to confirm when you try to throw something that is not intended to be thrown (for example, if you unwielded your bow and are now trying to throw arrows).