Java Edition 1.2.1

1.2.1 is an update which added a new height limit as a result of the anvil file format, zombie sieges and generated features including jungle biomes, wooden bridges in abandoned mine shafts, and desert wells. It also added new blocks/items - the bottle o' enchanting, redstone lamp, fire charge and chiseled stone brick and new mobs - iron golems and ocelots.

General

 * Warning Message
 * Worlds created prior to 1.2 will say the message, Must be converted!

Gameplay

 * Zombie Sieges
 * Will occur occasionally at night in NPC Villages

World Generation

 * Jungle biome
 * A very dense, but rather uncommon biome featuring large jungle trees that can reach up to 31 blocks tall with 2×2 thick trunks. Oak trees are also common. Leaves cover much of the forest floor.
 * Desert wells
 * Rarely found in deserts
 * Abandoned mine shafts'''
 * Generated with wooden bridges in midair portions

Blocks & Items

 * Bottle o' Enchanting
 * Can be used to spawn experience orbs.
 * Only available in creative mode
 * Chiseled Stone Brick
 * Only available in creative mode
 * Fire Charge
 * Produces fire when used
 * Can be fired from dispensers
 * Also a substitute for flint and steel
 * Redstone Lamp
 * Visually resembles Glowstone
 * Gives off light only when it is powered
 * Has a luminance of 15 when powered
 * Jungle Wood
 * New type of wood that spawns as jungle tree trunks
 * Has a slightly mossy brown texture with horizontal bark
 * Jungle Sapling
 * Can be grown into Jungle trees and drops from Jungle leaves
 * Jungle Leaves
 * Generates in Jungle trees and bushes
 * New textures (SandstoneGlyphs-Unused.png SandstoneFace-Unused.png)'''
 * Not in-game
 * Planned to be used as decorative sandstone variants

Mobs

 * Iron Golem
 * Occasinally spawns in Villages
 * Defends Villagers against Zombies and other hostile mobs
 * Can be spawned by placing 4 iron blocks and pumpkins in a specific pattern
 * Ocelot
 * Can be tamed using fish as cats
 * Cats will scare off creepers and teleport to the player similarly to dogs

General

 * Anvil file format
 * New map file format
 * Increases the world height limit, from 128; to 256
 * World selection screen shows worlds saved in Region file format, and will convert them.
 * No longer shows worlds saved in Alpha level format.

Gameplay

 * F3 debug screen
 * New Legends
 * lc: Largest section height
 * b: Shows what biome you are in
 * bl: Block brightness
 * sl: Sky brightness
 * rl: Raw brightness
 * Multiplayer
 * Due to biome data saving to chunks, SMP servers no longer send clients their world seed, displaying as "0" to the client
 * Third person view
 * Now has a slight delay on the speed at which the head moves on the player
 * Makes it possible to see the sides of the player's head

Blocks & Items

 * Dispenser
 * Changed texture
 * Grass
 * Placing blocks on grass will replace it
 * Ladders
 * Re-added collision box
 * Crafting recipe now yields 3 ladders instead of 2
 * Lava
 * Lava now has a faint rumbling sound effect, and large particles that hop out of the lava produce a popping sound
 * Oak Sapling
 * Changed texture
 * Slabs & Stairs
 * Can be placed upside-down by placing them below a block
 * Crafting recipe for slabs now yields 6 instead of 3
 * Vines
 * Can now be climbed like ladders

Mobs

 * Cave Spider
 * Swim extremely fast with the water stream towards the player, but seem to be almost not moving against the water stream
 * Creepers
 * Now stalk the player
 * Villager
 * Will have children if there are enough empty houses in a NPC Village
 * Wolf
 * Tamed wolves are able to breed using bones
 * Zombie
 * Can break down doors on Hard and Hardcore mode
 * Have a rare chance to drop an iron ingot, iron helmet, iron shovel, or iron sword
 * Rush to the nearest shadow or body of water for safety if it catches fire in daylight
 * Chase and attack villagers and doors (breaking them on Hard and Hardcore difficulties)
 * Sometimes zombies attacked villagers in preference to the player, and always chose the shortest way to the target, even if there was a door in the way
 * Skeleton
 * Have a rare chance to drop a bow or an enchanted bow
 * Rush to the nearest shadow or body of water for safety if it catches fire in daylight
 * Snow Golem
 * Will melt and die in the Nether
 * Will form a wall to attack mobs
 * Zombie Pigmen
 * Have a rare chance to drop a golden helmet, gold ingot, golden sword, or an enchanted golden sword
 * Swim fast in water

Fixes
3 bugs fixed


 * Doors have been updated so that double-doors work better with redstone.
 * Ambience works in Multiplayer.
 * Mob spawners show the correct mob in SMP (instead of a pig).

Further revisions

 * 1.2.2 fixed an issue with world generation.
 * 1.2.3 fixed some crashes that were present in 1.2.1 and 1.2.2.
 * 1.2.4 added new types of wooden planks, sandstone blocks, chat history, and a bunch of bug fixes.
 * 1.2.5 added "Pick Block" key, cats more eager to sit, and a handful of bug fixes.