Various items in Dungeons of Dredmor can be obtained though crafting. They require ingredients/materials, minimum crafting skill level and sometimes having first to learn the recipe (done by interacting with Bookshelves or certain skills (e.g.: Communist)).
To see which items can be crafted using which tools and ingredients, click any tool icon below:
Certain Skill will also let you Encrust items. To to so, click the "Encrust" tab on the top left corner of the crafting pane, and insert the item to be encrusted into the box that appears on the right side of the Pane.
When an item is inserted, the game will automatically filter to display only encrusts that are compatible with that item type. If you want to view the full list of encrusts your character knows, simply keep the box empty.
If an encrust is a Secret Recipe, you'll need to find separate versions for different item types. e.g. If you find the Joint Lubricant recipe for armors, you still won't be able to apply that encrust recipe to Pants type items until you also find the version of Joint Lubricant that works on pants.
Each time you encrust an item, it has a percent chance to gain a "terrifying side-effect, which is likely to lead to your death," based on its current instability score, and it then gains instability based on the encrust chosen. Since all items start with zero instability, this means that you will never gain a side effect on your first encrust of a given item. Further, the chance of gaining an instability has nothing to do with the encrust you are currently applying, and only considers the total instability score of the previous encrusts.
Instability gained is displayed as a broken purple star icon on the encrust tool tip, but the total amount of instability accumulated on your item is not displayed. So you must keep track of it manually, if you want to know how unstable your item is.
For example, if a player applies 3 encrusts, which have instability values of 5, 15, and 40, in that order, the percent chance of gaining an instability side effect are 0%, 5%, and 20%. Adding a 4th encrust after that would mean facing a whopping 60% chance of instability.
Instabilities are almost always bad. The least terrible ones inflict random teleportation and explosions centered on yourself, which some builds might be able to take advantage of, or at least put up with. Others inflict sleep, blindness, stat debuffs, various flavors of damage over time, item corruption, writhing tentacles bursting from your flesh and Evil Lich Magic.
Once an item has gained an instability side effect, any further encrusting risks worsening that instability, which not only adds another random terrifying side-effect, but also makes the existing ones more severe. Side effects that are merely annoying at low levels can be deadly when stacked and combined.