Complications are display mechanisms on a watch. Some, like hour, minute, and second, are taken for granted, while others are so rare and difficult as to be considered “Grande Complications” (see below).

The following complications are commonly found on many watches

• Hour hand, minute hand, second hand (not always considered complications)
• Date and day indicators, including “big date”
• Second timezone or GMT hand
• World timer
• 24 hour hand
• Day/night indicator
• Subdials for second timezone, GMT, 24 hour time, or small seconds
• Retrograde hands
• Power reserve indicator
• Moon phase
• Alarm function
• Chronograph functions
  • Hour, minute, second
  • Split seconds
  • Rattrapante
  • Countdown
  • Flyback
  • Foudroyante

Many people only consider complications related to time-telling when counting. However, a number of watches feature other non-timing features or complications, including the following

• Barometer
• Temperature
• Altimeter
• Depth gague

More elaborate functions are often used to demonstrate the technical skill of a watchmaker. These Grande Complications are often so important that they are the focal point of a watch. Some, like the tourbillon, perpetual calendar, and repeater, can command hundreds of thousands of dollars and are hallmarks of a prestige manufacture. For example, see the Patek Philippe Sky Moon Tourbillon Ref. 5002 with twelve complications, the IWC "Il Destriero Scafusia", the Jaeger-LeCoultre Hybris Mechanica series, or the Vacheron Constantin Tour de L'Ile, depicted here.

Some consider a watch to be “Grande Complication” if it includes any of the following rare complications. Others demand that a watch have more than one of these. Still more consider a watch to be a “Grande Complication” only if it includes complications from three categories Timing, chiming, and calendar.

Grande complications include

• Tourbillon, gyrotourbillon, or carousel
• Repeater and Grande Sonnerie
• Perpetual calendar with leap year
• Sidereal time
• Equation of time
• Astronomical indications, including sunrise and sunset and zodiac

Watchmakers occasionally “flex their muscles” by releasing special extremely-complicated watches, singularly or in tiny numbers. Such is the case for the most famous complicated watch, the Henry Graves Supercomplication by Patek Philippe. This pocket watch, commissioned in 1925, has set consecutive records when sold at auction, most recently selling for CHF 23.2 million ($23.8 million) on November 11, 2014 at Southeby's in Geneva. That same month, to celebrate their 175th anniversary, Patek Philippe released a limited edition of seven Grandmaster Chime wrist watches, their most complicated ever, with more chiming functions than any other watch.

• Die Reparatur komplizierter Taschenuhren; Author Bruno Hillmann; ISBN 3898806596 ISBN 978-3898806596