A weapon is a tool or device intended to cause pain, incapacitation, injury, or death. Transformers of every sort and every allegiance use a wide variety of weapons, both in war and in occasional peacetime pursuits (such as the hunting of turbofoxes).
Transformer weapons may be broadly classified as melee weapons, which are hand-held or affixed to the body, and used to directly attack an enemy; or as ranged weapons, which can attack from afar. Ranged weapons can be further classified into groups that involve material projectiles or missiles, and directed-energy weapons, which fire a beam or ray of energy. Directed-energy weapons are often called ray guns, beam weapons, or simply blasters. The technical specs for many G1 characters called their weapons lasers, despite stated properties that had little to do with actual lasers (examples include Springer's wind-tunnel laser and Kup's "musket" laser).
Weapons used to create a burst of flame, (flamethrowers, in layman's terms, though the mental image this word brings up is often quite misleading) such as those used by Slag and Inferno, are generally classified as directed-energy weapons, though there is a strong argument to be made for classifying them as melee weapons instead due to their limited range and often devastaing effects in close quarters.
Yet another distinction exists between those weapons which are accessories and may be wielded at will, and those which are built-in, inherent to a Transformer's body. For example, Tantrum may attack with his hand-held sword, or with the electrical dischargers built into his horns.
Transformers toys are equipped with a polymer arsenal of pantomime destruction, and here again there are several classes of weapons.
Weapons may be a permanently attached feature of either or both modes. Sometimes these are elements of one mode that are not otherwise used in the other except as detail and to simulate a weapon. Hot Rod's triple exhaust pipes, simulating forearm blasters, are a good example. Melee weapons may also be added this way, as when a figure's beast-mode claws are left in a position accessible for combat use. Other times, they may be clearly weapons in both modes, such as Armada Megatron's main cannon.
Accessory weapons may also be given. Guns are common, as are missile launchers. Often these attach to the main figure with pegs, though some use other means. One notable exception, the Alternators line, features guns with square handgrips, and posable fingers to hold them, but these weapons still use pegs to keep them against the figure's palm.
Any of these weapons may be no more than dummies, molded to look like weapons, or they may be functional. This function usually involves launching missiles, but it may instead use electronic lights or sounds.