The topic of undergarments and kilts has been the subject of many heated discussions around the worlds. According to popular mythology, true Scotsmen do not wear undergarments with kilts. However, there is plenty of evidence to the contrary, suggesting that the issue may be more of a personal choice than a dress standard.
There are certain situations in which wearing underwear with a kilt is required. At the Highland Games, for example, participants are asked to wear briefs or boxers for modesty reasons; the color of these undergarments is expected to coordinate with the kilt. Highland dancers also wear undergarments with kilts, since they engage in high kicks and other moves which could result in exposure of the area in question.
Supposedly, some military regiments require “traditional Scottish” dress, which is a polite euphemism for “nothing under the kilt.” However, pipe bands associated with regiments require the use of undergarments, since pipers use a high-stepping march, and many members of the military probably also prefer to wear undergarments under kilts for comfort reasons. Kilts are often very scratchy, because they are traditionally made from wool, and it can also get quite breezy under an unbifurcated garment, which could result in discomfort.
The military history of undergarments and kilts supposedly includes a period in which the uniform of Highland regiments did not include underwear. More probably, the roots of the idea that undergarments are not worn with kilts come from older Celtic cultures, which wore variations on the kilt, but certainly did not always wear undergarments. The Celts usually tucked long shirts or tunics under their kilts for comfort; this practice is still used by modern kilt-wearers who choose to eschew undergarments.
For casual wearers, most people say that the choice of undergarments is an entirely personal one, and a polite person should not inquire about the state of affairs under a kilt. Undergarments with kilts are certainly practical from the point of view of comfort and modesty, with some kilt wearers suggesting the happy medium of wearing underwear when ladies are present, while undergarments need not be required for all-male gatherings.
Kilt wearers are certainly tired of being asked about whether or not they wear undergarments with kilts. Some authorities suggest when asked “anything worn under the kilt,” men should respond “no wear, everything is in perfect condition, thank you for asking.”