A watch "complication" is a watch function that does anything other than relay the time. For aficionados of high-end watches, the more complicated, the better.

Making the parts of a watch is a painstaking procedure, but it pales in comparison to fine watchmaking's most difficult and prized creation, the complication.

Popular Watch Complications

The most common elements of a complicated watch are:

• Calendar
• Time zone indicator
• Split-second chronograph: Watch that both displays the current time and acts as a stopwatch
• Moon phase indicator
• Minute repeater: Watch that chimes out the hours with tiny hammers on gongs
• Retrograde: Hand that springs back to its starting point after gliding around the arc of the dial)
• Tourbillon: Rotating frame that counters the effects of gravity on accuracy) are the most common watch complications.

Watches that combine two or more are known as grande complication watches. Only master watchmakers, who typically spend several months assembling just one watch by hand, are sufficiently apprenticed to be able to create these.

Complicated To Make, Easy to Admire

A watch’s complications are, next to its design, the features that its collectors most value. Complications are also, to some extent, the measure of a watch’s intrinsic value, as distinct from its perceived value in a given market moment.

They are a direct culmination of centuries of artisanal tradition. “Every complicated movement in fine watches is over 150 years old,” says François-Henry Bennahmias, president of Audemars Piguet North America. “It is absolutely amazing that watchmakers were able to invent and put to work these intricate movements without computers. Their tools were their own eyes and hands. Such movements as the sunrise, sunset and moon-phase, just to mention a few, are hard to fathom as a creation of the human mind.”

As their name indicates, complications are--complicated. They are tiny, difficult to manufacture and difficult to manipulate. “They’re beyond the ability of most watchmakers,” Thomas Mao says.

Mao owns ThePurists, a clearinghouse for and by watch collectors. He’s been personally collecting watches for 30 years, observing the market and the industry and writing about it for specialized watch magazines.

“Tourbillon repeaters or rattrapante (split-second) chronographs, for example, are difficult to make even by the most experienced watchmakers,” he says. “These are the most likely to hold their value and be sought after.”

Complicated Watches Collectors Love

Minute repeaters chime the time in hours and fractions of the hour and in minutes, while tourbillons rotate at set intervals to limit gravity’s impact on a watch’s movement.

As collectible watches with minute repeaters go, no brand is valued more highly, according to Mao, than Patek Philippe. “Their watches consistently embody complication qualities such as low background regulator noise, clarity and purity of tone and sound volume,” he says.

Vacheron Constantin is also valued among collectors for its consistency of sound, as is Audemars Piguet for its breadth of quality repeaters.

One watch brand, the Panerai, is so fervently beloved that its collectors have their own fan club and are known as "Paneristi."

The Mystique of the Tourbillon

Possibly the most difficult to make and therefore most revered complication is the tourbillon. French for “whirlpool” or “vortex,” a tourbillon negates the effects of gravity on a watch by providing a precisely calibrated method of timed rotations.

The watch is more accurate with a tourbillon than it would be without it, but that’s hardly the point—no watch will be more accurate than a quartz.

No, the real oohing and aahing that a tourbillon inspires is simply in the incredible intricacy and difficulty of making it.

World's Most Complicated Watch

Vacheron Constantin’s Tour de l’Iles, with 834 parts and 16 complications, is the world’s most complicated double-face watch. At least for now.