Crafting success and exceptional quality
From UO:PvE Wiki
How recipe skill windows, secondary skills, talismans and exceptional-quality rolls work.
Development source reviewed on 29 October 2026. In-game availability is unverified.
Reading a recipe#
Each recipe lists a minimum and maximum for the main crafting skill. Every additional required skill must meet its minimum before the craft can succeed. The success calculation then uses the main skill’s effective Value; the secondary skills do not multiply the success chance.
Let S be your main skill, L and H the recipe’s minimum and maximum, and P0 the craft system’s chance at the minimum. The calculation is P = P0 + ((S − L) / (H − L)) × (1 − P0). A matching crafting talisman adds its Success Bonus divided by 100. The engine compares the result against a random number from 0 up to, but not including, 1. A zero chance cannot start a craft; reaching the listed minimum is therefore insufficient in a system whose P0 is zero.
| Craft | Chance at the recipe minimum |
|---|---|
| Bowcraft and Fletching, Carpentry, Tailoring | 50% |
| Alchemy, Blacksmithing, Cartography, Cooking, Inscription, Masonry | 0% |
| Glassblowing | 50% for Hollow Prism; 0% for other recipes |
| Tinkering | 50% for Potion Keg and Faction Trap Removal Kit; 0% for other recipes |
Exceptional quality#
Exceptional quality has a separate random roll. Recipes marked non-exceptional always return zero exceptional chance. Otherwise, remove a matching talisman’s success bonus from P before applying the exceptional formula below. A matching talisman’s Exceptional Bonus is added only when the resulting exceptional chance is positive.
For Blacksmithing, Cooking and Tailoring, exceptional chance is P − clamp(0.60 − (S − 95) × 0.03, 0.45, 0.60). For Bowcraft and Fletching it is P × 0.5 − 0.10. Other crafting systems use P − 0.60. Negative results cannot pass the random roll. A successful craft and an exceptional-quality result are distinct checks; the recipe maximum is not a promise of exceptional output.
Checks outside the chance formula#
A selected special material can require a minimum base crafting skill, independently of the effective skill used in the success formula. Tools, stations, resources, client expansion support and learned recipe IDs can also prevent a craft. Inscribing a spell scroll requires that spell in an accessible spellbook. Runebooks additionally consume one unmarked recall rune; the catalogue includes that shared-code requirement.
Blacksmithing requires an anvil and forge within two tiles. Glassblowing requires a forge within two tiles, learned Glassblowing and at least 100.0 base Alchemy. Masonry requires learned Masonry and at least 100.0 base Carpentry. Tinkered faction traps and faction trap removal kits require faction membership. Registration in a craft list does not establish that the training, recipes or ingredients can currently be obtained.
Source notes
Show 16 references
These references identify the reviewed shard files. Source presence does not establish live availability.
Projects/UOContent/Engines/Craft/Core/CraftItem.cs:813
Exceptional chance, independent rolls, success formula and skill requirements.Projects/UOContent/Engines/Craft/Core/CraftItem.cs:631
Selected-resource base skill requirement.Projects/UOContent/Engines/Craft/Core/CraftItem.cs:705
Runebook unmarked recall-rune requirement.Projects/UOContent/Engines/Craft/Core/CraftItem.cs:923
Client expansion, learned recipe and ordinary crafting checks.Projects/UOContent/Engines/Craft/Core/CraftSystem.cs:55
Default exceptional-chance rule.Projects/UOContent/Engines/Craft/DefAlchemy.cs:30
Alchemy minimum chance.Projects/UOContent/Engines/Craft/DefBlacksmithy.cs:26
Smithing exceptional/minimum chance; station check at line 93.Projects/UOContent/Engines/Craft/DefBowFletching.cs:23
Fletching exceptional and minimum chance.Projects/UOContent/Engines/Craft/DefCarpentry.cs:23
Carpentry minimum chance.Projects/UOContent/Engines/Craft/DefCartography.cs:26
Cartography minimum chance.Projects/UOContent/Engines/Craft/DefCooking.cs:23
Cooking exceptional and minimum chance.Projects/UOContent/Engines/Craft/DefGlassblowing.cs:24
Hollow Prism exception, training and forge requirements.Projects/UOContent/Engines/Craft/DefInscription.cs:45
Inscription minimum chance and known-spell check.Projects/UOContent/Engines/Craft/DefMasonry.cs:24
Masonry minimum chance and training requirements.Projects/UOContent/Engines/Craft/DefTailoring.cs:31
Tailoring exceptional and minimum chance.Projects/UOContent/Engines/Craft/DefTinkering.cs:40
Tinkering special minimum chances and faction checks.
Category: Crafting & resources