Weapon class
Seventeen kinds of weapon, and what each is for.
Every weapon is one of seventeen kinds:
Dagger, Sword, Axe, Mace, Gammer, Spear, Halberd, Staff, Wand, Bow, Crossbow, Gun, Fist, Claw, Scythe, Whip, Throwing.
The kind matters because a spell can require one: a spell that wants a Staff cannot be cast with a Bow in hand.
Class requirements
A piece can also require a class: either one class, or a class group, fighter (Paladin, Warrior), ranger (Rogue, Archer), caster (Magician, Priest) , and the requirement is on the piece’s page. Swords and axes are fighter pieces, daggers, katanas, bows and the whip ranger, staffs caster. The fourth group, combat, is gear for every class that is not a caster, fighters and rangers both (it was the old “not caster” requirement, renamed in 0.4.53); the edges, the scythes, the Ice Blade and the Chains carry it. Since 0.4.52 a piece whose class is not your active one can still be equipped and stays on through a class switch, but gives none of its stats until the matching class is active again.
Range
Most weapons reach one tile. Some add range on top of that, so a +2 weapon strikes from up to three tiles: +1 on the common bows, the Bone, Fluon and Octem crossbows and the throwing stars; +2 on the Lotus Longbow; +4 on the Compound and the Crossbow; +5 on the Long Bow, Death Bow and Ocean Bow; and +60 on the Lasergun. Each weapon’s page states its own. There is no minimum range: a bow can still be used on an adjacent target.
Tools
Some weapons are tools, and swinging one at the right thing harvests instead of attacking: a pickaxe mines, an axe cuts wood, and there are farming tools, fishing rods, catching nets and unboxing tools. See gathering.