An engraving refers to any form of text inscribed into the ground; the act of engraving refers to any act of inscribing such text in the ground, usually invoked with the command shift + e. The concept includes carving or burning characters into the dungeon floor, writing on the floor with a writing instrument, and drawing in the dust with fingers, wands, etc. This can ostensibly be done by a player to record messages to themselves, and there are also random engravings left in the dungeon; however the most common use of engraving is to inscribe the name Elbereth.
Engraving techniques may be classed as fast (fingers, wand, athame) or slow (other edged weapons, hard gems, gemstone rings). A fast engraving method takes 1 game turn per 10 characters engraved; if you engrave less than 10 characters by a fast method, it is instantaneous (this distinction is explained in detail below); otherwise, it takes 1 game turn to write 10-19 characters, 2 game turns to write 20-29 characters, etc. A slow method takes 1 game turn per character.
A non-instantaneous engraving isn't done until after the turn(s) have passed. This is a concern for two reasons: firstly, while players reading a spellbook or eating a food ration will stop when approached by hostile monsters, characters busy engraving will insist on continuing the job; secondly, if you are trying to engrave Elbereth, you are only protected once it is complete. So you can be killed while doing a non-instantaneous engraving (you will be described as 'helpless' in the death reason). Note that none of the engraving counts as being done until all the turns are passed (even if you could have written part of message in less time, no part of the message is on the ground until the whole time has passed); and not even any existing engraving on the floor counts as being present until the time is passed. So doing a non-instantaneous engraving obscures any existing engraving of Elbereth until the turns are complete.
There is therefore a lot of danger in doing a non-instantaneous engraving lasting more than 1 turn. And there is no advantage to doing so; for slow engraving, you can engrave 1 letter per command, and for fast engraving it is actually faster to split up your message and engrave 19 characters each turn. So you almost never want to do a non-instantaneous engraving lasting more than 1 turn.
Furthermore, if you are very fast and you know that you will get two turns in a row, you might be able to safely do a non-instantaneous 1 turn engrave: 1 character slowly or up to 19 characters quickly.
Instantaneous engraving is much simpler and safer. It uses only one player turn (so you may get multiple instantaneous engraves per game turn, if fast or very fast, via the usual speed system). Your engraving takes immediate effect, like most other simple player commands; in other words, an instantaneous Elbereth is on the ground before the monsters take their next move. You aren't helpless, and any existing engraving on the ground is not obscured while you engrave.
The engravings themselves may be classified as permanent (will not degrade), semi-permanent (will degrade slowly), or temporary (will degrade very quickly).
Permanent engravings are burned into the floor with a wand of fire or wand of lightning. The wand of lightning can blind you if your eyes are not protected. (Note that the blindness takes effect after the engraving is completed--you will not increase your risk of misengraving through blindness.) Permanent engravings will not erode from being stood on or walked over, but can be eliminated through techniques such as engraving over them or engraving with a wand of polymorph.
Semi-permanent engravings are carved into the floor with an edged weapon, a hard gemstone, a ring containing a hard gemstone, a wand of digging, or written with a charged magic marker (consuming one charge for every two letters). Engraving with any weapon other than a non-cursed athame will make the weapon dull (reduce enchantment) to a minimum of -3, at which point the weapon is too dull to engrave any more. (If it is not cursed, an athame will engrave forever without dulling. This, and its speed, make it highly prized as an engraving tool.) The weapon ordinarily suffers a -1 degradation for every second letter engraved, but a loophole in how this calculation is done can allow you to write longer messages by breaking the engraving job up into smaller parts: engraving three letters is still only a -1 penalty, so it is possible to use a +0 weapon to engrave three letters, then add three more, and then another three, for a total of nine characters before the weapon is useless, rather than only seven if you had attempted to engrave all at once. This is especially important when engraving the eight-character word Elbereth. Semi-permanent engravings can erode over time as they are walked over or stood upon, but not nearly as quickly as will temporary (finger) engravings.
Temporary "engravings" (actually just drawing in the dust on the floor) with your fingers by responding "-" when asked what to engrave with, or you can use another object such as a soft gemstone, or any wand other than fire, lightning, or digging (certain wands may have undesirable effects on the engraving itself, such as polymorphing it). This is fast, but subject to the 1/25 chance of mis-engraving per letter, and any movement, such as fighting or throwing missiles, will damage the engraving. Even standing still on the engraving will eventually degrade it, as no one stands perfectly still. Temporary engravings can also be erased with a towel. Attempting to write in the dust while polymorphed into a demon or vampire will instead scrawl in blood, which shares properties with writings in the dust.
Chances of Engraving Edit
You are not guaranteed to engrave perfectly if you are impaired or writing in the dust. For each letter, you have a (cumulative) chance of messing up if you are blind (1/11), confused (1/7), stunned (1/4), or hallucinating (1/2). If you are writing in the dust (with fingers, a wand, a soft gem, etc.) or scrawling in blood, you have a 1/25 chance of messing up each letter.  Riding also makes it more difficult to engrave properly. This is not usually much of a concern unless you are engraving "Elbereth," since an error there renders the word powerless (note that attempting to write "Elbereth" in the dust only works about 72.1% of the time as a result). If you can see, you can inspect your work with the "look" command, ':'.
Temporary engravings have about 3 characters corrupted per player combat action taken while standing on the square. Moving off of the square corrupts between 1 and 5 characters (but not jumping off or onto a square, or moving on to a square). And there is a (small) random chance every turn for the square on which the player is standing having between 1 and 3 characters erased. Notice that the number of characters corrupted is not dependent on the length of the message on the ground; so with a long message on the ground, the rate of degradation can be quite slow, hence the effectiveness of writing lots of Elbereths in the dust.
Semi-permanent engravings only have at most 1 character corrupted per action. Combat and movement both have about a 1/13 chance to corrupt a character.
Additional Notes Edit
- The epitaphs on gravestones share these properties, for obvious reasons.
- Using a magic marker to engrave graffiti on the floor is generally seen as a waste of the magic marker, but is also the most common type of writing used for engravings that are randomly generated in the dungeon.
- Burning with a wand of fire or lightning into ice will instead melt letters into the ice, which is like a semi-permanent engraving.
- Engraving may also be used to identify wands.
- When you name an item, it is possible to get a message such as "While engraving your hand slips." The mechanics of engraving and naming are separate and quite different; the message is part of an internal mechanism to preserve the unique naming of artifacts. This is certainly a special kind of engraving, because it is absolutely permanent and requires no tool at all!
- The limit of 9 or 19 characters per turn is due to the way C handles integers. (Characters/10) is truncated to 0 with up to 9 characters, and truncated to 1 with up to 19 characters.
See also Edit