Good things about second Ed: http://arcona.wordpress.com/2009/08/04/add-2nd-edition-the-one-you-love-to-hate/
1st vs 2nd Ed:
http://forum.rpg.net/showthread.php?260728-I-Need-Help-Choosing-AD-amp-D-Editions/page5
1st) Monks, Illusionists, Bards (fighter/thief, like a prestige class), Barbarians, Cavaliers, Thief-Acrobats, half-orcs, subtypes in UA 2nd) Specialty priests/mages, Bards (mage/rogue)
1st) Secondary skills/profession, optional: NWP 2nd) NWP
1st) weapon vs armour table (each weapon had an advantage) - historical simulation 2nd) weapon-type vs armour (simpler, but some items straight up worse), fighting styles
1st) 3" meaning 30 feet indoors and 30 yards outdoors 2nd) consistent
1st) Thief skills all the same, modified by dex/race 2nd) Thief puts points into skills
Combat and Tactics has updated weapon charts
3.x Edition: Use Jump from 3.0. Jump from 3.5 lets 1st level characters achieve olympic level jump records (for running long jump).