|Weapons and armor (and sometimes other items) can be damaged by combat or other means on occassion. There are two types of object damage: structural damage, and edged damage.|
Structural damage occurs when a large amount of force is inflicted upon an item. The more flexible the object's material is, the less likely it is to be damage by force. For example, an object made of stone is very inflexible and thus will be more likely to break under stress than a softer material such as wood. Some metals are more brittle than others; for example, steel is more flexible and thus less likely to break than iron. Completely flexible materials such as cotton are immune to structural damage.
Edged damage occurs when a sharp blade is applied to an item. Harder materials are more resistant to edged damage than software counterparts. For example, objects made of stone are very unlikely to sustain edged damage, but soft items such as cloth, leather, or wood are fairly susceptible to edge damage. Most metals are in the middle; soft metals such as bronze or gold will be easier to score than hard metals such as iron.
Once an object has sustained a certain amount of edged or structural damage, it will become bent or torn (depending o the material type). Once in this state, it will only be half as effective as usual. Further damage will have a chance of destroying the item completely, making it unusable. The amount of damage an object can sustain is based on its quality and its weight.
Some objects are made of more than one material, and each material sustains its damage separately. So you could find that your axe's head hardly ever gets a scratch while its haft is constantly getting cut up when you block with it.
If you are in need of repair for your items, you should seek out someone with skill in craftsmanship. You can quickly check which of your equipment has sustained either wear-and-tear or major damage with the assess command.