In watchmaking, a complication is any function a watch performs beyond displaying the hours, minutes and seconds. That covers a lot of ground: a simple date window, a chronograph that times an interval, a GMT hand that tracks a second time zone, a perpetual calendar that knows the leap years through 2100, and the tourbillon that Abraham-Louis Breguet patented on 26 June 1801 to fight gravity's pull on the regulating organ. Read as a category, complications are less about what a watch tells you and more about how far the maker pushed the movement to tell it. For most collectors, this axis is where mechanical fascination really begins.
Real examples make the spread clear. The chronograph is the everyday favourite: the manually wound Omega Speedmaster Professional Moonwatch sells in steel for roughly £5,900 to £6,200 in 2025. For travellers, the Rolex GMT-Master II averages around £15,000 and ranges from about £9,500 to well over £80,000 by reference, with a 2025 model introducing Rolex's first ceramic Cerachrom dial. On the calendar side, Patek Philippe's annual calendar, patented in 1996 and needing only one correction a year, appears in the moonphase ref. 5396 at roughly £51,000 in a 38.5mm case. More accessibly, Longines builds a Valjoux 7751 moonphase chronograph in the Master Collection around £2,200, while the Certina DS-8 Moon Phase opens the door under £450.
When you shop this category, start by asking which function you will genuinely use. A frequent flyer gets daily value from a GMT; a fan of timing events is better served by a clean, legible chronograph; a perpetual calendar dazzles but carries higher service costs and needs careful setting if it ever stops. The general trade-off holds: the more complications a watch carries, the thicker the case, the pricier the service interval, and the trickier the resale liquidity. One well-executed complication almost always satisfies more than three poorly integrated ones.
The far end of the category is instructive too. At the top sit grand complications that combine several high-end functions at once: the Jaeger-LeCoultre Master Grande Tradition Grande Complication runs around £320,000, and Vacheron Constantin's 2025 Les Cabinotiers Solaria Ultra, built for the brand's 270th anniversary, packs 41 complications into Calibre 3655 with 1,521 components. Few buyers need that, and that is fine. The sensible path is to start with one complication that fits your life, learn how the movement behaves, and climb from there.