|Damage vs. small||1d3|
|Damage vs. large||1d3|
|Base price||60 zm|
A luckstone is a gray stone that modifies a player's Luck and Luck timeout. A noncursed luckstone adds 3 Luck (which may exceed the ordinary maximum of 10) and a cursed luckstone subtracts 3 Luck. Luckstones carried in containers (e.g. bags) have no effect on Luck.
A cursed luckstone prevents the timeout of negative Luck, blessed ones prevent the timeout of positive Luck, and uncursed ones prevent both. For example, if you have a blessed luckstone and jump a lot in Sokoban, your total Luck will time out to three.
Multiple luckitems have no cumulative effect. You get the blessed luckstone effect if you have strictly more blessed than cursed luckitems in your open inventory, the cursed effect if the other way around, and the uncursed effect if equally many blessed as cursed (or all uncursed).
Luckstones are always generated uncursed except possibly in bones files.
There is a guaranteed luckstone in each of the three variants of Mines' End.
You should BUC-identify your luckstone so you can see when it gets cursed. Blessing it is not terribly important because there is no difference to an uncursed one as long as your Luck is not below its baseline value (though it's useful so spellcasting enemies have to curse it in two steps).
A backup luckstone carried in a container or left in a stash may be useful in case your primary luckstone becomes cursed, assuming uncursing is limited (differently named, blessed luckstones in your inventory can help retain positive luck after facing a cursing monster).
Identifying a gray stone
If you find a gray stone, DO NOT pick it up right away. First, make sure this is not a loadstone by kicking it (see identification of gray stones for more details). If it is, #name it on the floor (if you can) and leave it alone.
Second, rub it on an iron item: a touchstone will sound "scritch, scritch". Archeologists can skip this. Blessed touchstones are useful to identify gems, but that is out of scope.
If both tests are negative, this is either a luckstone or flint stone. You should pick it up and type-#name it until you get two different kinds or have a chance to price-id it: luckstones cost 60, flint doesn't interest shopkeepers. If a monster with the attribute "likes magic" picked it up, it's not flint.
As long as you don't know whether it is a luckstone or flint stone, treat is as a luckstone. Luckstones are initially uncursed, so they are safe to carry around (barring bones or bad Luck).
In versions of NetHack prior to 3.6 (and some variants based on these versions) it was possible to determine if any given gray stone was a luckstone by trying to name it "The Heart of Ahriman" (the naming artifacts exploit). If the stone was a luckstone, your hand would slip and give it another name; if it was not, the attempt would succeed. This was fixed in version 3.6: attempting to name any unidentified gray stone "The Heart of Ahriman" will fail, regardless of the stone's actual identity.
You have a luckstone: Max your Luck and keep it
Once you have a known luckitem to prevent Luck timeout, you want to max out your Luck. This is a useful part of any ascension kit; do so before you go to Gehennom. Good ways to increase your Luck are:
- throwing precious gems to co-aligned unicorns (formally identified gems give 5 Luck each; type-named ones give 2),
- sacrificing powerful monsters on a coaligned altar (you gain 5/24 of the value in Luck (value is usually equal to difficulty, with a few exceptions)).
Most players will want to keep their luckstone in their main inventory at all times once they have maxed out their Luck. However, if you don't mind the tedium and are very conscientous, it is somewhat safer to bag it and take it out only when it prevents Luck timeout: on turns divisible by 600, or by 300 if your god is angry or if you are carrying the Amulet of Yendor (although you could just drop the Amulet).
There are notable exceptions to this max-and-keep Luck strategy:
- A cursed luckstone belongs in a container. Likewise for a bones level luckstone until you test it (pet, altar, identify spell, or scroll of identify).
- If your Luck is below its baseline value, drop or bag all non-blessed luckstones every 600th turn (300th if your god is angry at you) until you fix it or wait it out.
- Altar work requires Luck <= 9 to avoid getting crowned when praying. The easiest way to control your Luck is to max it out, then to break mirrors, squeeze onto a boulder or jump in Sokoban, break eggs laid by you, or kick a cross-aligned altar. Keep your luckstone, and watch those sacrifice messages!
- Blanking scrolls and potions by stepping into water becomes inefficient with high Luck.
- This is 1 on full moons, -1 on Friday the 13th, 0 with both of the above, and 0 otherwise.