The Smart-Disc, also known simply as the Disc, is a thrown Yautja weapon. It is an extremely sharp circular cutting device that is typically thrown like a discus and yet returns to the user like a boomerang. It also features a hand grip for use as a melee slashing weapon as well.
Computer-controlled gyros guarantee that the Smart-Disc returns to its wielder when thrown and also give the weapon a degree of auto-guidance, allowing it to alter its course in mid-air and follow a moving target if necessary. While Smart-Discs apparently guide automatically, some can be directed in flight using the targeting laser built into the Predator's Bio-Mask. It is also capable of tracking multiple targets with one throw, giving it capabilities against large groups of enemies that most other Yautja weapons do not posses. Its devastating razor edges are capable of cutting through most substances with ease — a Smart-Disc has been seen to cut through half a dozen cattle carcasses and a man in quick succession without any effort. However, in the event that the Disc becomes embedded in a solid material, it can be returned to the thrower with the push of a button on the Predator's Wrist Gauntlet.
Some Smart-Discs shrink in side (usually by telescoping shut in one direction) when not in use, for ease of storage about a Predator's person; this telescoping action also apparently activates and deactivates the Disc's systems. Others have been seen to have teeth-like serrations around their circumference.
It is stated in the video game Aliens versus Predator: Extinction that the Disc's flight is mentally controlled by the Predator; only Predators who train their mental capacity, known as Disc Masters, are able to do this. Discs may also be upgraded with a nanovibronic edge, in essence a high speed molecular chainsaw around their circumference that can tear through even hardened composite armors. Furthermore, it is possible for a Predator to embed a nanovibronic Smart-Disc within an opponent and then activate the weapon's "haywire mode". Needless to say, few enemies fare well with berserk ripping machines embedded in their internals.