The 1.3 update for the PC version of Minecraft is going to completely revamp the game to its core, and one of the most important changes to single player will improve gameplay altogether.
In essence, there will be no more single player mode. Instead, single player will be a “shell” on top of multiplayer, making the game run faster. This means that single player will just be multiplayer with only one player in it. The tradeoff will be that PCs were require a little extra juice to run the game, but the transition between playing alone and in multiplayer will be minimal.
Other updates in the 1.3 update will include new resource: Emerald, which can be used for currency with villages. Players can also get books to write in, tripwire for traps, new craftable items, some new sub-biomes including Desert Hills and Ice Mountains.
The full changelog for 1.3 was posted in Reddit, and includes the following (warning, this is a super-long list):
General
Improved overall stability and performance
- Reduced CPU, RAM & bandwidth usage
Made Singleplayer internally use a Multiplayer server
Added optional single-player commands called "Cheats" on non-hardcore worlds
- Type
/and then hit tab to autocomplete & get help on various commands - Most commands from MP are available
- Type
Added option to let LAN friends join SP games
- You can choose which gamemode players join in and whether they are allowed to use cheats
Added demo mode for non-premium users
- Lasts 5 game days per world
Added chat options
- Change which parts of chat are shown and how opaque it is
- Toggle chat colors, links being clickable and warning prompts for links
- Option to rebind the command key, which opens the chat with
/in the textfield
Mobs can now spawn on top slabs and upside down stairs
Improved F3 mode:
- Truncated coordinates to 5 fractional digits
- Removed frame rendering time history graph (bottom-left)
- 3 new values:
ws: Walking speed (constant)fs: Flying speed (constant)g: Boolean value, true when you touch the ground
Updated language files
- Added tooltips for all types of Monster Egg blocks and the End Portal Frame
- Added more descriptive tooltips for different types of tree-related blocks, sandstone and stone bricks
- Localized server commands
- Added missing commands-related strings
- Added missing double chest GUI caption
Fixed many bugs
- Fixed texture packs in folders not showing their icon and description
- Fixed Man-in-the-middle attack allowing hackers to log in as you when you visit their server
- Fixed the Open texturepack folder button not working on OS X
Gameplay
Added Adventure mode
- Only playable using commands
- Building, setting things on fire and using buckets is disabled
- Players can only interact with mobs and the environment
Added trading
- Screenshots
- Using emerald as currency, villagers will, depending on profession, offer different trades to players
- There are three kinds of trades: Selling, buying and enchanting
- As displayed in the top-most part of the trading GUI, villagers take one or more items or item stacks and give back something
- After trading, villagers will sometimes emit purple particles for a few seconds to indicate that their trades changed
- Otherwise unobtainable bottles o' enchanting and chainmail armor can be obtained by trading
Improved Creative mode inventory
- Screenshots
- There are categorized tabs for various groups of items and blocks
- Added a search tab which will automatically be switched to when the chat key is hit
- Added survival inventory tab, which shows the full inventory, a 'Destroy item' slot, armor slots including a preview of your character and a 2x2 crafting field
- Items can now be deleted from the inventory by shift-clicking them
- Added layered snow block, Monster Egg Blocks (Silverfish spawning blocks), Ender Portal frame and all potions
- Now shows potion effects' timers like in Survival
Improved experience collection
- Depending on ore type, experience now drops from ores that drop items
- Taking smelted items out of furnaces gives experience now
- Destroying mob spawners gives experience now
- Adjusted experience level progression:
Levels 1-15cost 17 XP points eachLevels 16-30cost 3 more XP points than the previous (cost = 17 + (level - 15) * 3)Levels 31-∞cost 7 more XP points than the previous (cost = 62 + (level - 30) * 7)
Improved enchanting
- The new maximum level with bookshelves is 30, without 8
- 15 bookshelves are enough to reach level 30
- The 3rd slot shows the most expensive possible enchantment more often
- Increased chances for multiple enchantments at once
- Adjusted enchantments' to go with the new maximum level
Added writing in books
- New crafting recipe for books: 3 pieces of paper and one piece of leather in any possible shape
- New item: Book and Quill - Crafting recipe: 1 ink sac, 1 feather and 1 book in any possible shape
- Right-click to write on & edit up to 50 pages or read
- Click 'Done' to save the book, 'Sign' to choose a title and finalize the book
- Screenshots
Improved Multiplayer
- Made entities less likely to glitch through blocks - Comparison: before and after
- Added automagical downloading of standard sized texture packs when joining servers
- Made server commands more descriptive
- Added reason parameter to
/ban - Added
/seedcommand to show the map seed - Added
/defaultgamemodecommand to choose the gamemode new players start in - Added
/debugcommand to enable and disable profiling /kickmessages can now contain "\n" to force a new line- Blocks other players are mining now show cracks - Screenshot
/tpcan now be used to teleport to specific coordinates- Made server list re-orderable: shift+click or shift+arrow keys move selected servers
- Server list now scans for LAN servers - Screenshot
- Added hardcore difficulty: Players are banned upon death
Added many minor things
- Individual, stackable items near each other on the ground now become one item stack
- Added shift clicking support to armor slots, brewing stands & enchantment tables
- Added setting to disable servers offering you texture packs
- Made the stars smaller and brighter - Screenshot
- Villagers spawned from spawning eggs will get a random profession now
- Removed the downwards knockback while drowning
- Doors being broken by zombies now show their damage - Screenshot
Improved the Pick Block key
- You now get the actual block
- You can now pick paintings, boats, minecarts and mobs, which will give you their spawn eggs
- Picking huge mushroom blocks now gives mushrooms
- You can no longer pick portal blocks
Fixed many bugs
- Fixed flying slowly in liquids
- Fixed blocks with the same id but different data/damage values stacking in Creative inventory
- Fixed boats & minecarts not being one-hit breakable in Creative
- Fixed raw fish, dyes, saddles, potions, milk buckets and tools depleting in Creative
- Fixed water destroying non-solid blocks when breaking them from above
- Fixed Silk touch giving you only one slab from double slabs
- Fixed redstone updates not propagating through unloaded chunks
- Fixed arrows scooting up to the top of the block they were shot on in MP
- Fixed repeaters getting stuck when loading their chunk
- Fixed endermen not opening their jaws in MP
- Fixed tools taking damage when breaking insta-breakable blocks
- Fixed fully charged arrows not showing their particle effect in MP
- Fixed many sounds not playing in MP
- Fixed magma cubes' and slimes' jumping animations not showing in MP
- Fixed thunderstorms not darkening the sky in MP
- Fixed weather not fading in or out in MP
- Fixed enchanted armor and tools not glowing to other players
- Fixed ender pearls and eyes of ender not being aligned in the inventory
- Fixed explosions not pushing players back in MP
- Fixed TNT not knocking back players in MP
- Fixed pistons not pushing back players in MP
- Fixed the arrow representing players on held maps being offset
- Fixed being able to duplicate sand, gravel and powered rail
- Fixed placing a piston in front of another powered, but not extended one resulting in a glitched piston with the head's texture on all sides
- Fixed TNT dropping as a ressource on creative mode
- Fixed powering specifically glitched pistons crashing the game
- Fixed players on minecarts, boats or pigs and spider jockeys not being displayed in the correct location
World Generation
Made sub-biome type mountains like Desert Hills or Ice Mountains taller - Screenshot
Made cocoa beans appear on some small jungle trees - Screenshot
Added optional starting chest on non-hardcore worlds
- Screenshot
- Contents: wooden & stone tools, bread, apples, logs, planks and sticks
Added large biomes world type, increasing biome sizes immensely
Added desert-specific villages
Added desert temples
- Screenshots
- Built out of various kinds of sandstone and wool
- Include hidden chest room and TNT trap, with loot including rotten flesh, bones, iron ingots and gold ingots, diamonds and emeralds
Added jungle temples
- Screenshots
- Built out of various kinds of cobblestone
- Contain multiple tripwire traps triggering dispensers filled with arrows
- Loot chests include bones, rotten flesh, gold ingots, iron ingots, diamonds and emeralds
Added emerald ore
- Only generates in Extreme Hills biomes
- Occurs up to 8 times per chunk in veins of 1
- Generates between layers 4 and 31, inclusive
Blocks & Items
Emerald Ore
- Screenshot
- Drops Emerald
Emerald
- Screenshot
- Is used to trade with villagers
Block of Emerald
- Screenshot
- Crafted by putting 9 emeralds on a crafting table
Ender Chest
- Screenshot
- Crafted by surrounding an eye of ender with 8 pieces of obsidian
- Stores each player's contents across dimensions and all Ender Chests
- Contents are preserved even if all Ender Chests are destroyed
- Explosion-resistant
- Emits light and purple particles
- Unless mined using a Silk Touch-enchanted pickaxe, they drop 8 obsidian
Tripwire Hook
- Screenshots
- String in between needs to be placed manually
- Breaking the string triggers a redstone signal, cutting it using shears doesn't
- Entities like boats, mobs, arrows or players touching the string trigger a redstone signal
- String can be up to 40 blocks long
- Crafting recipe: Iron ingot on top of a stick on top of a wooden plank
String
- Can now be placed on the ground decoratively
Furnaces
- Can be fueled by wooden tools now
- Return an empty bucket when using lava buckets as fuel now
Ice
- Instead of melting in the nether, it now disappears
- Can be obtained using Silk Touch-enchanted gear now
Glass Panes
- Can be obtained using Silk Touch-enchanted gear now
Nether portal
- Leaks into the Overworld now: Depending on difficulty, zombie pigmen rarely spawn in them
Half slabs
- Added all wood types
- Wooden slabs crafted after the update act like wood
- Will now be top slabs when placed on the upper half of a block's side
- When placed upside down, rails, pressure plates, levers, doors, torches, redstone torches, repeaters, redstone dust and beds can be placed on them - Redstone dust behaves like on glowstone - It transmits power horizontally and upwards, but not downwards. Redstone torches don't power redstone placed on slabs/stairs above them.
Stairs
- Added Sandstone Stairs - Screenshot
- Added wooden stairs for all kinds of wood - Screenshot
- Adjusted hitbox - Screenshots
- When placed upside down, rails, pressure plates, levers, doors, torches, redstone torches, repeaters, redstone dust and beds can be placed on them - Redstone dust behaves like on glowstone - It transmits power horizontally and upwards, but not downwards. Redstone torches don't power redstone placed on slabs/stairs above them.
Leaves
- Water slowly drips through them when it's raining
Cauldrons
- Slowly fill up when it's raining
Dispensers
- Minecarts & boats will now be placed if there's rails/water in place
- Instead of dispensing buckets, dispensers will now suck in or place water or lava in front of them
Gravel
- Changed texture - Screenshot
Jungle leaves
- Have a 1/200 chance to drop a cocoa bean when destroyed now
Lever
- Can be placed on the ceiling now - Screenshot
Wooden pressure plates
- Are triggered by arrows now
Pistons
- Changed a few things to fight bugs, which now causes them to appear to update slightly slower - some contraptions may require changes to signal timing
Cocoa beans
- Retextured item - Screenshot
- Can be planted & grown on jungle wood nowimg
- Can be grown instantly using bone meal
Cookies
- Give a full hunger point now
Empty buckets
- Stack up to 16 now
- Stacked buckets work just like stacked glass bottles do
Signs
- Stack up to 16 now
- Crafting now gives 3 signs instead of 1
Golden Apple
- Has two crafting recipes now, the new one replacing gold nuggets with gold blocks
- Second tier gives Regeneration IV, Resistance and Fire resistance effects
- Only second tier glows like enchanted tools
Spawners
- Added NBT tags to further customize spawned mobs
- Only changeable using map editors or mods
Boats
- Are not broken by lilypads anymore, instead they run straight through the lilypad now, breaking and sometimes dropping it
- Are less glitchy and more responsive now
- Increased maximum speed
- When exiting, players will be moved from the boat
- When broken, they drop a boat now
Minecarts
- When on rails, they can be accelerated a bit while sitting in them
- When exiting, players will be moved from the minecart
Mobs
Pigs
- Drop 1-3 meat now
Slimes
- Reduced spawn rate in superflat maps
Silverfish
- When suffering from poison potions, they will now spawn more silverfish from nearby silverfish blocks more often
All hostile mobs
- Become aggressive towards the last mob or player that hit them now
