An acquirement is a specific way of generating an item in Crawl that, unlike most item generation, is based in large part on your character's abilities and possessions. It is guaranteed to be usable or equippable. The item is biased towards being both good and useful to your character, but your luck may still vary. You may be given an item that allows you to win the game, or you may be given useless junk.
There are only a few sources of acquirements. Most are fairly rare, and those that are more common tend to be not as good. The sources are:
- Reading a scroll of acquirement gives the player an acquirement, with a choice of item type. These are quite rare and valuable.
- Three deities can give out acquirements:
- Okawaru gives out weapon, armour, and ammunition acquirements on a fairly regular basis at high piety. These weapons are biased toward worse item types than those created by other sources.
- Trog gives out weapons, usually antimagic branded, and ammunition at high piety. Similar to Okawaru, Trog's items are biased towards having slightly worse base types than other sources of acquirements.
- Xom may occasionally give you acquirements, among all the other junk thrown at you.
- Items in vaults may be created using acquirement code; the most notable example of this would be items in treasure troves. As these items are placed when the trove is created, the player obviously cannot choose their type, but they generally are biased toward your predominant skills. Not all excellent items found in vaults are necessarily acquirements, though.
Acquirements are affected by a number of different factors:
- They are biased towards items that match your skills. For instance, a character who has heavily invested in Maces & Flails is fairly likely to receive a weapon in that category should they opt for a weapon acquirement. Similarly, a conjurer who uses mainly Fire Magic will likely find themselves receiving a spellbook with more spells from that school should they choose a spellbook acquirement.
- They are biased against items that you have already seen, the logic there being that if you have seen it, you're probably either using it or have decided it isn't useful. This usually includes items in shops, but those which are far too expensive for your character to buy at present are excluded from being "seen."
- The item is guaranteed to be usable. This means that you will be able to equip it, and using it will not incur penance with your current deity. Note that these guarantees are fairly minimal: acquirement may well give your Armour-based hill orc a robe (although it will be biased against doing so if you have invested in the Armour skill).
- The item will not be cursed (although it may curse itself upon being equipped, if it possesses that particular ego). Worshipers of Ashenzari will always receive cursed items.
- Your species and god may also cause changes in the items given. For example, Ghouls will receive chunks as food, and followers of good gods won't receive weapons of draining.
Note that acquirements are not directly affected by your current depth or location. However, the bias against items you have already seen means that later acquirements do tend to give out rarer items, as the common ones have already been seen. This can often produce better acquirements later on, although how much better depends on the item type asked for, and saving an acquirement for later runs the risk of you dying due to poor equipment before you get the chance.
Specific acquirement types
You receive a branded, randart, or even possibly unrandart melee or ranged weapon that usually belongs to the weapon schools you are skilled in. It helps if you are skilled only with weapons that you really want to use in combat.
You receive a good or randart piece of armour or shield, with a small chance of an unrandart. The creation process does consider your skills and even mutations, but the item is not guaranteed to be useful for you. However, it will always be one that you are capable of wearing.
You receive a random piece of jewellery, sometimes a randart. The game will try to give you something you have not identified yet, but there is no guarantee. The chance for a randart is flat and does not depend on the amount of jewellery you have identified.
You receive a randart spell book or manual. Melee/ranged combat players are less likely to receive spellbooks. Worshipers of Trog will always receive a manual, but never one that trains magic. Randart spellbooks will tend to include spells from the player's most knowledgeable spell school.
You receive a magical staff based on the following conditions:
- If your best magical skill is Fire Magic, Ice Magic, Air Magic, Earth Magic, Poison Magic, Conjurations, Necromancy or Summonings you may receive the matching staff (50%), or a non-enhancer staff (a staff of wizardry, power, or energy).
- Otherwise you may receive completely random staff (33%) or a non-enhancer staff (i.e. your best skill is Spellcasting, or you already are carrying your best skill's staff).
You receive a large amount of gold, from 220 to 5520 gold coins (Mean=1218, Median=880, Std=911). This can help you go on a shopping spree in a bazaar, obtain an expensive randart in a shop for a treasure trove, or provide you with some opportunities to use Gozag's abilities.
- Felids can only choose between five categories: Jewellery, Book, Evocables, Food, and Gold.
- Mummies and Vampires cannot acquire food.
- Prior to 0.24, Vampires could acquire 8-12 potions of blood as food.
- Prior to 0.21, Fedhas worshippers received fruit, and other species could get royal jellies as well as rations - this was removed when food was merged into rations.
- In 0.20, wand and misc acquirement were merged into evocables.
- In 0.19, ammo acquirement was removed, and randart jewelry appeared twice as often as before. Prior to 0.19, rods were obtained through [e] Staff acquirement rather than [g] Misc Evocable.
- acquire.cc:1344 (0.24.0)