40d:Item quality

All items in the game have a base value, which is multiplied by what material the item is made of and by the item's quality. Decorations (such as bone, gems, and studding) further increase the value.

Item quality can have an effect on an item's properties, especially armor and weapons.

Quality grades

All crafted items (furniture, armor, bolts, etc.) – but not intermediate materials (bars, blocks, etc. except cloth, which does have quality levels) – are bracketed by characters that show the quality of their craftsdwarfship. Dyeing also has a quality level, as does Decorating/Encrusting (with gems, leathers, cloth, etc). Prepared foods have quality levels. Alcohol has a hidden quality rating that controls the amount of happiness a dwarf gets from drinking it. It is not yet known whether the damage or destruction of masterful alcohol can cause tantrums.

Designation	Description	Value Modifier	Damage / To-Hit / Armor Modifier
Item Name	—	×1	×1.0
-Item Name-	Well-crafted	×2	×1.2
+Item Name+	Finely-crafted	×3	×1.4
*Item Name*	Superior quality	×4	×1.6
≡Item Name≡	Exceptional	×5	×1.8
☼Item Name☼	Masterful	×12	×2.0
Unique name	Artifact	×120	×2.0

When a masterful quality item is created, the game will announce, "<dwarf> has created a masterpiece!" The destruction or theft of such a masterpiece will cause the dwarf that created it an unhappy thought. Trading a masterpiece item to merchants is always safe. Masterpiece meals can be eaten safely, although allowing the food to rot will provoke the same response as theft or destruction. Using masterpiece bolts will not cause a tantrum, even if the bolts break. However, if a kobold or wild animal steals a used masterpiece bolt which was lying around, then the maker's mood will decrease. If a bolt misses its target and falls into the chasm or is melted by "the impertinent magma", this also counts as defacement.

The magnitude of the unhappy thought is equal to 1000 divided by the number of masterworks the dwarf has created^[Verify]. So a engraver with hundreds of masterwork images on the walls of the fortress will be merely irked by the destruction of a one, while a a dwarf who has only made a single masterwork item would become deeply upset.

Since legendary dwarves are most likely to be the ones creating masterpieces, keeping these creations safe should be high priority; tantruming legendary dwarves can be very difficult to subdue.

Artifact items have a unique name instead of bracketing symbols and are worth 120x base value. Artifacts, like masterpiece items, will cause a significant mood drop in the creator when destroyed or stolen. According to inspections of the memory values, it seems that artifacts have the same quality value as masterpiece items, with presumably the same armor/weapon modifiers (×2.0)^[Verify].

Skill and quality levels

Tradesdwarves of different skill levels will produce items of differing quality. "Dabbling" dwarves never (without applicable preference) produce anything above a basic quality item, legendary dwarves usually produce Exceptional items, and the best legendary dwarves produce Masterful items approximately 27% of the time.

Preferences for particular materials and objects make a considerable difference. Although the exact adjustment is unknown, preliminary testing indicates that they can boost effective skill (not quality) by one to three levels (if the craftdwarf likes the item type, subtype and material).

Chance for	No quality	Well-crafted	Finely-crafted	Superior quality	Exceptional	Masterful	Average Value Multiplier	Jump in Average Value
Dabbling	100%						1.0
Novice	80%	18%	1.9%	0.13%	0.007%	0.00009%	1.2226	0.2226
No label	60%	32%	6.9%	1.0%	0.1%	0.003%	1.4924	0.2698
Competent	40%	42%	14%	3.1%	0.5%	0.02%	1.8114	0.319
Skilled	20%	48%	24%	6.8%	1.6%	0.09%	2.2428	0.4314
Proficient		50%	33%	12%	4.0%	0.28%	2.7036	0.4608
Talented		40%	36%	17%	6.6%	0.58%	2.9596	0.256
Adept		30%	37%	21%	10%	1.1%	3.182	0.2224
Expert		20%	37%	26%	15%	1.8%	3.516	0.334
Professional		10%	36%	30%	21%	2.9%	3.878	0.362
Accomplished			33%	33%	29%	4.4%	4.288	0.41
Great			27%	33%	34%	5.9%	4.538	0.25
Master			20%	32%	40%	7.7%	4.804	0.266
High Master			13%	31%	46%	9.8%	5.106	0.302
Grand Master			6.7%	28%	53%	12%	5.411	0.305
Legendary				25%	60%	15%	5.8	0.389
Legendary+1				20%	63%	17%	5.995	0.195
Legendary+2				15%	66%	19%	6.199	0.204
Legendary+3				10%	68%	22%	6.412	0.213
Legendary+4				5%	71%	24%	6.635	0.223
Legendary+5					73%	27%	6.89	0.232

The above table is based on the formula discovered by User:Bartavelle:

First, a skill level is computed, apparently directly related to the dabbling...legendary indicators. No skill or dabbling is 0, legendary is 15. It's capped at 20.

Item quality is set to 0.

Then dice are rolled. If a roll fails, no further rolls are made.

• If d5 < skill level, quality is bumped.
• If d10 < skill level, quality is bumped.
• If d15 < skill level, quality is bumped.
• If d20 < skill level, quality is bumped.
• If d25 < skill level and d3 == 1, quality is set to 5.

This gives the 6 quality levels (0 to 5).

According to inspections of the memory values, it seems that artifacts have a quality of 5.

Effect of quality on weapon skill ^{v0.23.130.23a}

To quote Toady:

The quality of any weapon, including crossbows used as launchers, affects the skill of the shooter. I think this even leads to obscene things like master crossbows + master bolts causing recruits to shoot like legends. In general, if the quality Q is from 0 to 5, the skill is modified according to

Skill_new = Skill_original × (1.0 + 0.2 × Q) + Q

This is pretty extreme and will probably be reduced for all weapons.

while equipped with a single masterpiece weapon, dwarves have skill increase to Accomplished, not Legendary. Still, the bonus is way too high. See this chart for the exact levels:

Note: This chart is out of date/wrong due to the facts that the integer that represents a specific skill level is not known, how the formula rounds is not known, and the fact that higher legendaries exist is known.

Result for	Well-crafted	Finely-crafted	Superior quality	Exceptional	Masterful
Dabbling	No label	Skilled	Talented	Expert	Accomplished
Novice	Competent	Proficient	Expert	Accomplished	Master
No label	Skilled	Adept	Professional	Master	Grand Master
Competent	Talented	Expert	Great	High Master	Legendary
Skilled	Adept	Accomplished	Master	Legendary	Legendary
Proficient	Expert	Great	Grand Master	Legendary	Legendary
Talented	Professional	Master	Legendary	Legendary	Legendary
Adept	Accomplished	Grand Master	Legendary	Legendary	Legendary
Expert	Master	Legendary	Legendary	Legendary	Legendary
Professional	High Master	Legendary	Legendary	Legendary	Legendary
Accomplished	Grand Master	Legendary	Legendary	Legendary	Legendary
Great and better	Legendary	Legendary	Legendary	Legendary	Legendary

If this is true, then it would be possible to:

1. Train a couple dozen skilled miners
2. Give them exceptional picks
3. Draft them and give them decent armor
4. Kill a goblin siege with a couple dozen legendary speardwarves (picks = 70% damage spears) as long as there are no enemy champions to destroy your armour/shield/wrestling inept speardwarves