Drop

From Guild Wars Wiki

When a party kills a creature, it often drops loot in the form of items or gold. Items are assigned to a single member of the party (which could be a henchman or a hero, in which case the item never manifests in the world), but gold is shared equally between all party members.

Normal foes can generally only drop a single item, while bosses can generally drop up to three items. Note that quest items and festival item drops are independent of normal drops. Some players also argue that killing an entire mob of enemies instead of just one or two can also lower the drops/drop rate if they die at the same time.

Ownership of an unclaimed drop expires after 10 minutes

Loot can also be obtained from chests.

Some of the most coveted drops in the game are rare and unique items.