Castle has a very sophisticated inventory system, limiting a player's load based on weight (measured in grams) and bulk (measured in cubic centimetres) rather than number of items, and allowing the character to use different types of containers as packs.
- Packs and Bags (small, medium and large), each having a weight and bulk of their own plus that of their contents, and a maximum weight and bulk, but no maximum number of items.
- Chests (small, medium and large), which occupy their maximum bulk regardless of how full they are, but otherwise resemble Packs.
- Belts, which have a fixed number of slots in addition to the maximum weight and bulk. The Utility Belt and Wand Quiver Belt have specialty slots that can hold only specific types of items. Potions, Scrolls, Books and Wands can only be activated when on the belt, worn in place of a belt, or carried in the Free Hand.
- Purses, which work the same way as packs, with high capacity, but can only carry money.
- Enchanted Packs of Holding (small, medium and large), the only magical containers, which (unless nearly empty) weigh less and take up less space than their contents. Enchanted Packs repel each other magnetically, so unlike all other containers, they will not nest.
CoTW has many slots for wearable items. In addition to one for each type of item listed below, there are slots for Purse, Pack, Belt and Free Hand (the latter three unrestricted as to type of object held).
- Suits of Armour of many types, such as Leather Armour, Studded Leather, Chain Mail, Splint Mail, Plate Mail, Plate Armour, Elven Chain Mail and Meteoric Steel Plate Armour.
- Shields made of several materials (Wooden, Iron, Steel, Meteoric Steel), each of which can be small, medium or large.
- Helmets in Leather, Iron, Steel and Meteoric Steel. A Helmet of Detect Monsters also exists.
- Bracers and Gauntlets. Enchanted bracers will always increase armour class, enchanted gauntlets will increase strength, dexterity, armour class or both chance to hit and damage.
- Boots, which add a small amount of Armour Value, and if enchanted, can also increase the player's speed or cause him to levitate. Cursed boots will slow the player down. All boots are made of leather, unlike some other RPGs which include chain boots, etc.
- Cloaks (worn in the Overgarments slot), which are worn under armour and provide a small amount of Armour Value. Enchanted Capes of Protection are cloaks with an even higher Armour Value boosts.
- Rings and Amulets. Enchanted rings will raise one attribute or armour class, enchanted amulets will increase the resistance to an element or undead stat draining. Cursed amulets will limit your carrying capacity ("Cursed amulet of burden") or will reduce your resistance to an element.
- Many types of weapons, with a wide variety of possible enchantments and curses, but all reaching only into adjacent squares (no bows etc.) The strongest weapons are two-handed swords, which can not be wielded while you hold a shield. The second strongest are bastard swords.
- Staffs, which can function both as wands and as weapons. The spells staffs can cast are different from, and generally stronger than, those a wand can cast.
Items to be Activated
Before these items can be Activated, they must be placed on the belt, or directly on a body slot (usually Free Hand).
- Potions and Scrolls, with a wide variety of magical effects. Healing spells, Detect Objects, Detect Monsters and Detect Traps can be performed by both potions and scrolls; Levitation is performed only by a potion; and other spells in the game only by scrolls. In addition, Scrolls of Map Quadrant and Map Level exist, and some special potions restore Mana or allow the character to gain experience or permanently increase attributes.
- Books, each containing a spell that the player can learn. Learning the spell is permanent, but consumes the book. A player will instantly recognize a book for a spell he already knows, and so will always learn something new from an unidentified spellbook, while you should make a bundle selling known spellbooks.
- Wands, which cast a spell and have a certain number of charges.
- Scraps of parchment, at three key points in the story, each displaying a message when Activated (read), after which they disappear (crumble or burst into flames).
The basic and smallest unit of currency in CoTW is the copper piece (CP). Larger units include the silver piece (1 SP = 10 CP), gold piece (1 GP = 100 CP) and platinum piece (1 PP = 1,000 CP). Each of these coins weighs 1 gram and takes up 1 cubic centimetre.
In the second and third towns, a bank exists that will allow the player to deposit his or her money. This money remains spendable, but takes up no space in inventory and cannot be stolen.
Each town has several stores, each of which will buy and sell only items of certain types. All stores will pay the same price for any item, regardless of the character’s attributes or point in the story, and will buy items of any quality (except cursed or worthless items). However, they vary in the quality of items they will stock.
All stores will pay more for an identified item that is found to be normal than for one that is unidentified (see below for exceptions) but will not treat it as a worthless item. If too many unidentified items sold to one store turn out to be cursed or worthless, the store will refuse to buy any more.
When they buy an item, they will identify it and put it up for sale; if it is a wand or staff, they will recharge it by two charges, unless it shatters while being recharged (random chance).
Each town also includes two special stores:
- Olaf's Junk Store, which sells nothing but will buy anything, including the "worthless" items that other merchants reject, for which it pays 25 copper pieces (CP). However, it will not pay more than 25 CP for an item, even when other merchants will. In some cases, such as boots and purses, it is more profitable to sell undamaged versions here, rather than to the usual shops, because the other shops will not pay more than 25 CP for them.
- The house of a sage, who will identify any unknown item for a fee.
Normal, cursed, enchanted or worthless?
Almost every item in the game can be normal, cursed or enchanted, with curses and enchantments working the same way as in NetHack. Although items do not break in use, many can be broken or rusted out, and thus useless, when the player finds them. Since rings, amulets, potions, scrolls, wands and staffs are valued only for their magical effects, the non-magical Ring of Adornment, Necklace of Adornment, Distillation of Water, Blank Scroll, Dead Staff and Dead Wand are also worthless, and are the only ‘normal’ items which become ‘worthless’ (still worth 25 CP to the junk store) when they are identified. Bracers, gauntlets, cloaks and boots also decrease in value when they are identified as normal: any of the 4, when unidentified, will fetch 250 CP in the proper store, but only 60 CP for bracers or gauntlets identified as ‘normal’, and only 15 CP for a cloak identified as a ‘wool cloak’ or boots identified as ‘normal leather boots’. However, unless you plan on cheating by identifying your items and then loading an earlier saved position with the knowledge of your items that you should not have, you should generally not sell these items to shops in unidentified status because the chance they are enchanted more than offsets the loss in value resulting in them turning out to be ‘normal’ or cursed. Packs and belts are never cursed, and so if you lack these items and you press the 'get' button, because there is no risk in equipping yourself with them, they will automatically be placed in the appropriate slots in inventory for their use, even in the case of a broken pack or belt which each have zero capacity. Many items in the game can be named, so you can call your sword "Excalibur" if you wish.