When playing with the 1.12 client, quest items will now be destroyed when abandoning quests, like the game's interface warns you. Food now increases your normal health regen like it does in Classic, instead of being on a separate timer. Guards will now turn to face you when you emote at them like in Classic.
You will no longer see an 'Absorb' message when a mob dies while a spell like Fireball is still traveling towards it. Hunter traps should now work in the Gurubashi Arena. Small fixes have been made to multiple quest scripts around the world. Corrected spell ids used by a lot of mobs around the world. Mobs attacked by a guardian pet will now be correctly tagged for the owner of the pet. Items in the vendor buyback menu will now display properly after teleporting. Improved Hurley Blackbreath's script in BRD. Added many missing Ore and Herb spawns. Implemented the Belfry Bats event that happens every hour in Brill. Aggro and stealth detection ranges have been adjusted to match Classic. Imp pets now have a chance to say something on aggro like they do in Classic. Pet follow movement has been improved and pets should now be able to keep up with their owner better. Creature pets should no longer be missing their passive auras. Fixed mind control in pre 1.9 versions. Fixed some issues with the Nefarian fight in BWL. The final room in Uldaman has been improved. Several improvements to bosses in AQ20. Feign Death now has a timer and it will kill you for real when it expires like in Classic. Hunter bots will now cancel Feign Death once everyone around them has left combat. Druid bots will now leave their form if you switch them to healer. Warlock bots will now send their pet to attack upon entering combat. Repeatable quests will now continue to give XP on each completion like in Classic. It should be much more rare now for players to get stuck in combat. The Scourge Invasion event has received a complete rework and is now much more accurate. If you pull a single mob within a group, and it causes the other nearby mobs to also aggro, they will all become linked, and damaging one will extend the leash timer of them all. The creature leashing logic has been reworked to match Classic. Creatures who move in a group formation can now continue on their path after their leader has been killed. This makes spell damage closer to Classic. If a number is between two other numbers, it can now be rounded either up or down, instead of always being rounded down to an exact integer. All damage calculations now use floating point numbers. This allows you to do many of the tricks that were possible in Classic, like using Voidwalker's Suicide and Demonic Sacrifice at the same time to get both buffs, or swapping to a slower speed weapon at the same time you hit a mob to increase damage done by Seal of Righteousness.
There is now a small delay to all spell effects. Spell batching simulation has been implemented. Fixed several bugged spots in mmaps, that were preventing mobs from pathing there. That means pets and partybots can now follow you on elevators. Implemented server side movement support for elevators. Updated translations for Korean and Chinese languages to match Classic. This fixes bugs like being able to use a macro to see the armor of any mob in the game. This means the server no longer sends information that should not be revealed to players.
Private update fields have been implemented. The server no longer stores the 'sha_pass_hash' in the database, to make sure it's not possible to decrypt the passwords of players.
The format of map files has changed, so it's recommended to download the full version, unless you want to extract everything yourself.