Dwarves which repeatedly perform a specialized task will quickly gain skill levels, and within a year or two of constant labor (greatly depending on the skill) can attain Legendary ability. Tasks which do not involve time-consuming gathering of materials, especially mining and engraving, are easy to develop quite rapidly. If you have Proficient miners dig constantly through stone, they can reach Legendary skill before your first winter.
Dwarves which attain Legendary skill at any task will blink on the game screen and have a blinking name on the Unit screen.
Legendary is not the highest skill level a dwarf can attain. There are five invisible skill levels above it, all called "Legendary," but providing increasing skill. We've named them Legendary+1...Legendary+5. At Legendary+5, a dwarf will always produce at least ≡Exceptional≡ goods, whereas at Legendary through Legendary+4 *Superior* quality is possible.
 Benefits of Legendary status
 Increased productivity
Dwarves with Legendary skill work at a, well, legendary rate, and produce masterful goods more often. A legendary miner will mine roughly 14-15 squares to a no-label miner's one, for instance, and a legendary engraver can smooth 25 squares in the time it takes a no-label engraver to do one. The real-time rate is dependent on CPU speed: a Perfectly Agile legendary miner can mine about FPS×2 squares per minute, or FPS×4 ore squares. Dwarves with legendary item production skills are able to produce far higher quality items than dwarves of lower skill, if that item has a quality modifier attached to it (many do, many don't).
 Attribute increases
With skill increases also come attribute increases. Legendary dwarves are typically Strong, Agile, and/or Tough – sometimes superdwarvenly so.
The specific benefits of each attribute are:
- Agility: Agile dwarves perform all tasks faster. Perfectly Agile dwarves work at nearly twice the rate as non-agile dwarves, not counting skill differences.
- Strength: High strength will increase damage done in battleVerify. It will also reduce or eliminate the encumbrance penalty on a dwarf's speed. For example, a very strong dwarf isn't encumbered by full-plate steel whereas a dwarf with no strength attribute would be.
- Toughness: Tough dwarves are more durable in combat and heal much faster.
 Free rent
Like nobles, Legendary dwarves are exempt from the dwarven economy: they can take any object as a personal possession without paying for it, and claim any bedroom as their own without paying rent. This helps to keep them happy, although some Legendary dwarves may acquire an annoying number of objects.
 Speeding skill attainment
If you provide item-producing dwarves (Masons, Carpenters, Craftsdwarves, Brewers, etc.) with a constant supply of nearby goods, they can quickly increase their skill levels as well. However, such dwarves can quickly produce mountains of goods, so you must allocate huge stockpiles and many dedicated haulers in order to keep their workshops from becoming severely cluttered. Farmers with a nearby seed barrel and food stockpile can also gain skill quite rapidly.
 Strange moods
Dwarves which enter a strange mood and successfully construct an artifact object will gain one Legendary skill (with commensurate attribute increases) unless it was a "possessed" mood (which results in the creation of an artifact without a skill increase). The skill a dwarf gains from a strange mood will be the skill used in making the artifact, generally the dwarf's highest "trade" skill (most skills which involve the production of finished goods, though with a few exceptions - see here for a detailed list). If you have your peasants train to "dabbling" in desired skills (such as Armorsmith or Mechanic), you will greatly increase your chance of gaining dwarves with those skills at Legendary level.
 Cross-training Legendary dwarves
Because their attributes are so high, Legendary dwarves can quickly develop other skills to high levels as well. This is most useful when you have many redundant Legendary dwarves in certain professions but lack them elsewhere. It may be useful to deliberately train dwarves in a quick skill to get them to Legendary status, then switch them to other jobs.
As haulers are usually unskilled peasants, having them cross-trained is a good idea to improve their attributes. With more strength they can haul heavy items (or bins full of heavy items) faster, and with more agility they can generally move faster; resulting in more efficient hauling.
The Siege Operator skill is particularly useful for training dwarves. Siege operation does not train very quickly, since it takes a few years to gain Legendary skill; however, it requires little supervision - just build a catapult and set it to fire at will. Siege operation is not considered a "trade" skill, so it will not interfere with gaining useful skills through strange moods, and having a catapult operate continuously is a good way to clear an area of loose stone. Furthermore, siege engines are of little use in combat without skilled operators. Dabbling operators take minutes to load a single bolt or stone, whereas legendary operators can load and fire in a matter of seconds.