Buccaneers are a group of humans (or, occasionally, other races) that live outside of the law on the high seas. They waylay ocean travelers, harass fisher-folk and merchants, and may even take over entire port towns, if left unchecked. Buccaneers are self-interested above all, and vary with the level of cruelty they impose: some just want to make a living for themselves (if in a way outside the law), while others delight in cruelty and violence. Most buccaneers tend to be outside the law, but organized fairly well within their own clans (leading them toward Neutral or Neutral Evil alignments).
Large buccaneer groups are lead by fighters and theives of significantly high skill, spread fairly evenly throughout the hierarchy. The buccaneer leaders occasionally work together with skilled wizards and clerics of deities related to thievery, violence, or outcasts (the clerics tend to be a bit weaker than the wizards or fighters in the force).
Buccaneers outfit themselves well as warriors, with swords, shields, chainmail and leather armor, spears, bows, and crossbows. While they lack mounts, buccaneers are skilled ship captains, and can navigate most any craft on the seas better than their peers.
Buccaneers usually lair on a large ship. Occasionally, they dwell in cave complexes, in ruins, or in fortified structures they've build (or comandeered) themselves. Buccaneer lairs often have prisoners and camp followers such as merchants (noncombatants).