Here are the list of changes implemented in the 1.2 patch:

• 3 new maps: Skeltston Head, Asylum and Darkened Enlightenment.
• Improved versions of Th-Korman (higher fps) and Th-Spider (BSP free).
• Can now jump while crouched.
• Crouching when falling makes a quieter landing noise (50% quieter than normal).
• Slowed strafe to match walk forward speed.
• Guards are now 25% slower than thieves when crouched.
• Can fall on enemies' heads to knock them out (or crush them if you're a guard).
• Added the ability to climb on your teammates, letting the thieves boost each other over the hedges on Korman and suchlike.
• You now have to face torches to relight them.
• Shows teammate health on the HUD under their icon when you look at them.
• Team chat shows location ID at the start.
• Delay between dropping items so you can't abuse the supply chest for flares.
• Bow charge up time increased and arrow damage proportional to speed of the arrow.
• A slight knockback added to the arrows and bolts. Very satisfying to shoot an annoying sniper down from the rafters. ;)
• Moss arrows same price as caltrops.
• Health potions and food take some time to do their work.
• Mines have a delay before activating when dropped (stopped people using them like short range rocket launchers).
• Mines no longer explode when teammates tread on them.
• Fixed the supply chest disappearing bug when you bought a loudout after the game had started.
• Improvements to vines - very long vines work correctly, climbing cylinder centred around vine properly and arrow is easy to pull out.
• Crack arrows made more potent, with cracked players stumbling about in random directions (great for Flats rooftops).
• Moss goes invisible in the dark and is aligned properly on slopes.
• Food and potions now dropped when you die.
• Catfall also silences your normal footstep sounds.
• Can buy rations (cheap food) in the shop.
• Dropped loot automatically returns to the level after 60-120 seconds.
• Can frob objective items even if they're buried under junk (crosshair will go red).
• Fixed the weird teleporting lag behaviour when you bumped another player/AI in a netgame.
• Co-op options displayed on F2 screen.
• Breaking the Co-op no kill/KO rules only applies to hurting guards and only kills the one player, doesn't end the game.
• Fixed misc co-op bugs.
• Changed the way you join a team in a netgame. There is now 15 seconds at the start of the game to nominate your team. Players are then shifted about to make teams even, taking into account their choice and which team they were on last time.
• Thiefmatch and Co-op tabs in the server browser.
• Made the favourites tab in the server browser use the proper columns and not launch UT when you try to join a server.
• Server logs chat and IP addresses to the log file.
• Menu music plays correctly.
• Fixed map voting in coop/thiefmatch.
• Tweaked scoring, fixed some scoring bugs, a guard will get points when a thief steps on his traps.
• All the new levels have sketch maps which show the location of yourself and your teammates.
• A number of improvements to the co-op game, including a tab in the server browser, fixed map voting and co-op options shown on the F2 screen.
• Three spectator options: Rat, follow cam and free cam.
• Fixed a bunch of misc bugs and exploits.

Also see the changes that were made at 1.1 here (incorporated in this patch).

All content (c) Thievery UT team, 2002