[Indemaijinj]

Much is similar to Ad&d: Here is some of the differences:

The proficiency system replaced with skills and feats. Skills are the non-weapon proficiencies. You put ranks in them representing training. Some of them might be cross-class (and thus cost double), just like in Ad&d. How many points you get initially and per level is decided by your class and intelligence (capacity to learn). Thieving skills are also part of this system. Rogues gets more skill points than the other classes. Fighters gets less.

Weapon proficiencies have been done away with. Instead weapons have been sorted into three categories:

Simple weapons: Light easy to use weapons that most people can use.
Martial weapons: Larger weapons that require some combat training to use, generally only available for warrior-type classes.
Exotic weapons: Weapons so unusual or specialised that only a few chosen can use them properly. Unless your class specifically gives you proficiency with an exotic weapon you must use a feat for each exotic weapon you want to use.

Feats are a new concept that includes various neat abilities that includes weapon specialization, auxiliary proficiencies (classes only proficient with simple weapons can use feats to get access to some martial weapons) and various combat abilities that are not totally dissimilar to the BG2 HLA's (though generally not so overpowered). Metamagic (spell-enhancing) and Item Creation (allows for the construction of magical items) feats also exist. Fighters gets a lot more feats than the other classes.

The dice rolls and bonuses are now much more easy to understand. The saving throws are not arcane things such as Wands, Petrification/polymorph or Breath Weapon. Instead there is only three saves:

Fortitude: Things that can be averted by being tough and resilient. This is things such as diseases, poisons and harsh conditions.

Reflex: Things that can be averted by sidestepping or being wary and sure-footed. This is things such as traps, slippery surfaces and the likes.

Will: Things that can be averted by force of will. Things such as mind-affecting magics and resisting urges. (Will is also the more general Save vs. spell save).

Calculating to hit rolls is simple: Roll a d20 and then add any modifier there may be. Then compare it to the target's armor class. If it is equal or higher than the armor class the roll hits.

Both arcane (wizard, sorcerer, bard) and divine (cleric, druid, ranger, paladin) spells are now goes from level 0-9 (0 being cantrip effects). Psionic powers now also come from level 0-9. Except for the psionicists and the sorcerers the memorization and learning rules are the same as in Ad&d

Bonuses and penalties from ability scores are now spread more evenly on the scale. (The difference between Str 10 and 12 is the same as the difference between Str 16 and 18). The 18/xx ability scores has been done away with.

All classes now use the same XP table.

There is no level limits for non-humans (who played with them anyway?).