Drops

Drops are items which appear when mobs and some other entities die. There are three basic types of drops: normal drops, rare drops, and Experience Orbs. Only normal drops appear when a mob is killed other than by the player.

Common and uncommon drops
Common drops may occur whenever a mob dies, and appear at the location of the mob at the moment it receives the killing damage. Most mobs have particular items which it may drop when killed. There are also "uncommon drops", such as spider eyes, which don't always drop, but have a large (item-specific) chance to do so. Some uncommon and common drops don't drop at all if the mob was not "killed by the player" (same rules as for experience orbs).

For each of these items, there is a random (uniform) distribution of numbers of that item it will drop; for example, a cow will drop 0–2 leather items and 1–3 raw beef items. Since the range includes 0, it is possible for no leather to be dropped. If the mob is killed with a weapon with the Looting enchantment, then the upper limit of the range is increased by the level number of the enchantment.

If a mob is a baby animal, it will not drop anything when killed.

Rare drops
Rare drops occur in addition to the common drops. Unlike most common drops, they only occur if the monster is killed by a player. All rare drops except skulls can also be obtained by other means. Rare drops are always a single item, not multiples.

Rare drops have a 2.5% chance of occurring when a monster dies. Using a weapon with the Looting enchantment increases the chance by 0.5% per level (up to 4% with Looting III).

Each monster has a separate list of possibilities for enchanted rare drops and non-enchanted rare drops. Within each list, all items are equally likely.

Additionally to rare drops, a monster can drop equipment and armor that it's visibly wearing. Each piece of equipment that monster was spawned with is dropped with 8.5% chance. Looting increases this change by 1% per level (up to 11.5% with Looting III). This means it is possible for a zombie or skeleton to drop more than one piece of equipment upon death. All items that mob picked up after spawning are always dropped, even when the monster wasn't killed by a player. Baby Zombies, however, will never drop stolen items, even if the player kills them.

When items are enchanted, the enchantment is chosen in the same way as using an Enchantment Table with a cost of 5–15 levels on normal difficulty, and 5–35 on hard. On easy difficulty, equipment is never enchanted. It is possible to get multiple enchantments.

Experience Orbs
Experience Orbs only drop if a mob dies less than three seconds after being attacked (melee, bow, snowballs, eggs) by a player or by a player's pet wolf. Their total value will always be the specific amount of experience granted by killing that mob. They are also dropped from a thrown Bottle o' Enchanting. Collected experience accumulates into levels, which can be used for enchanting.

Experience Orbs are similar to items but not the same. Unlike other drops, Experience Orbs appear at the location of the mob's corpse at the moment it disappears in a puff of smoke. Experience Orbs will move towards nearby players.

Block drops
Most blocks drop themselves when broken. All special drops from blocks are listed below. "Silk Touch" column indicates, if the block can be collected using the Silk Touch enchantment.

Notes:
 * Blocks marked with "T" need to be broken with a specific tool to drop anything (including experience). The Silk Touch enchantment doesn't remove this requirement.
 * Where noted, Fortune can increase the number of dropped items or multiply it. Increase simply gives 0-lvl extra items. Multiplication happen with the following chances:
 * Fortune I: 33% * 2 (33% more on average)
 * Fortune II: 25% * 2, 25% * 3 (75% more on average)
 * Fortune III: 20% * 2, 20% * 3, 20% * 4 (120% more on average)
 * Container blocks (brewing stand, chest, dispenser, dropper, flower pot, furnace, hopper, and jukebox) drop themselves when broken along with their content.
 * All blocks not listed in the table above drop themselves when broken. Fortune doesn't affect their drop.

Trivia

 * Dropped weapons, tools, and armor from mobs will have at least 25 durability remaining, which is also the most common. Less-damaged items are increasingly rare. Except for gold swords and tools, items will always have at least 26 points of damage taken.
 * Due to Zombies and Skeletons rarely spawning with random armor, and having a 5% chance of dropping one article of said worn armor on death, it is finally possible to legitimately acquire chainmail armor without trading with villagers.
 * While skeletons will drop bows of differing enchantments, the most common seems to be "Power I."