Lambda logo



The Lambda logo is a symbol found frequently in the Half-Life universe.

Half-Life
In the original Half-Life, Gordon Freeman's trademark HEV Suit was marked with a Lambda Logo on the chest, as were other HEV Suits. A section of Black Mesa dedicated to teleport research was also called the "Lambda Complex".

Half-Life 2
Apparently, Gordon's Lambda logo on his suit and the work of the Lambda Complex became something of a trademark symbol for the quest to stop the Xen Invasion, because many years later, the citizens of the Resistance have adopted it as their symbol as well, referring Gordon Freeman acts during the Black Mesa Incident. They would spray-paint it near supply caches, and resistance bases such as White Forest, Black Mesa East, and Kleiner's Lab. Resistance fighters also wear the symbol on their arm bands. They are also used to identify Resistance-friendly Combine weapons such as Hopper Mines and Sentry Turrets, seen by the spray-paint on them.

Trivia

 * Lambda means (in scientific terms) the rate of decay of radioactive materials, which is related to the half-life of an element.
 * Lambda is used in some programing languages and parts of math to denote a function.