Light Weapons
A character is less unbalanced if they fight with Light Weapons. These weapons qualify for benefits from Finesse (if appropriate) and make Two-Weapon and Multi-Weapon Fighting easier.
Light Weapons
A Weapon is considered a Light Weapon if it is two Size Categories smaller than the character or more, is of the same Size Category (or smaller) and has the Light Tag or can be wielded one-handed by the character without Size Penalties and has the Light Tag. For purposes of determining this, consider Small characters to be Medium Sized when it benefits them.
For instance, a Dagger (Tiny) is considered Light to Humans and even Halflings (as being Medium size benefits them here). Meanwhile, a Rapier is considered Light by them as it has the Light tag, is of (effectively) equal Size. A Giant's Rapier could, perhaps, be wielded by these characters if they have the appropriate Heavy Weapons Style.
Unarmed Attacks
Brawling, Wrestling and Natural Attacks are considered Light if the character has Expertise or Specialization in them. This does not apply to Improvised Weapons, which qualify as per normal weapons.