Root Canal - No Anesthesia
Defeat Bile-Tooth

Near the beginning of the game, from Red Fang Goblin Lair you enter Bile-Tooth's Treasury and defeat the boss.


Element-ary
Enter the Elemental Planes for the first time

Near the latter part of the game you will be tasked with activating the elemental foundations by teleporting there from Omduil's Manor.

Open Season
Kill 100 Goblins

This will come naturally as you play through the game.


Kaboom-Shaka-Laka
Kill 3 enemies with a single explosive barrel

Can be done easily in the Sewers in the city of Baldur's Gate (see screenshot below for location). As you progress through the sewers you will enter a room blocked by normal barrels (the big ones) and a black powder barrel (smaller and lighter in color) with three rats that will try to reach you. Simply hit or shoot the black powder barrel to light the fuse, then wait for it to explode - there's a very high chance the rats will be close enough to die instantly.













Up Close
Kill 1000 enemies with a melee weapon

Self-explanatory, will come naturally during your playthrough (depending on playstyle).


Safety's Off
Kill 1000 enemies with a ranged weapon

Self-explanatory, will come naturally during your playthrough (depending on playstyle). I personally got this while doing a playthrough with the dwarf (Borador) using a crossbow...though bows and throwing knives should work as well.

If you don't plan on doing a playthrough with a ranged weapon, I recommend using the dwarf (Borador) and getting his Hail of Bolts skill to a high/max level (shoots multiple bolts at once) - the Accuracy skill will also help boost damage if needed. Combined with an upgraded crossbow you can 1-shot most enemies in the early areas of the game. Using the character import feature you can then start a new game, import your dwarf, clear everything including the sewers in town, save and then start a new game again to repeat the process until you get 1000 ranged kills.

The Vlad Touch
Do 2000 damage with Vampiric Touch

Play as the necromancer (Ysuran), acquire the "Vampiric Touch" skill and start killing.


My Buddy Drizzt
Defeat 500 enemies as Drizzt Do'Urden

You need to unlock Drizzt by finishing the game on any difficulty first. Once unlocked you can select Drizzt by picking the cleric (Alessia) during character selection and then pressing DOWN on your D-PAD. Either play just a bit past the sewer quest to get the 500 kills, or use Drizzt for your Extreme Mode playthrough.


My Pal Artemis
Defeat 500 enemies as Artemis Entreri

You need to unlock Artemis by finishing the game on extreme difficulty first. Once unlocked you can select Artemis by picking the cleric (Alessia) during character selection and then pressing DOWN twice on your D-PAD. You should get the 500 kills if you start a new game and kill everything up to a short way into Bloodmire Manor.

Important note on most of these achievements:

Once you finish the game for the first time, you will be asked if you want to create a savegame after defeating the last boss. If you want to get most of the playthrough achievements without having to actually play through the game with all characters, then keep this savegame around.

Using the character import feature (pause game -> change players -> import or new -> choose savegame or new character) after loading this savegame, you can import any character from a previous savegame or a fresh level 1 character. Once imported, just click on the black pylon, watch the end credits and the playthrough achievement is yours.

This works for all achievements requiring you to finish the game with a specific character as well as the co-op playthrough achievement.


I Did It!
Complete the game on any difficulty

Self-explanatory, just finish the game once on any difficulty with a character of your choice.


Extremely Satisfying
Beat the game on Extreme mode

Also self-explanatory. I wouldn't recommend starting a fresh character for this but rather using Drizzt (unlocked after finishing the game once on any difficulty) or importing the character you did your first playthrough with. If you import a normal character into an extreme mode playthrough, they will only retain skills and levels, not their items! Drizzt starts with very decent melee weapons so that makes things easier.


Table for Two
Complete the game in co-op mode

Just finish the game in co-op mode. This seems to require 2 controllers...at least I haven't been able to figure out how to have one player use keyboard/mouse and the other use a controller.


Alessia Made a Mess-a-ya
Complete a Human Cleric Playthrough on any difficulty

Finish the game with the cleric (Alessia).


Bora-down with Borador
Complete a Dwarven Rogue Playthrough on any difficulty

Finish the game with the dwarf (Borador).


Dorn Done Did It
Complete a Human Barbarian Playthrough on any difficulty

Finish the game with the barbarian (Dorn).


Vanquished by Vhaidra
Complete a Dark Elf Monk Playthrough on any difficulty

Finish the game with the monk (Vhaidra).


Ysuran Is The Man
Complete a Moon Elf Necromancer Playthrough on any difficulty

Finish the game with the necromancer (Ysuran).

Level Up!
Gain your first level

This will happen within the first couple minutes of playing the game.


I Can Sell Stuff?
Sell an item to the merchant in Baldur's Gate next to the Purple Wyrm

Just sell any item to the vendor in the city of Baldur's Gate. You can find the vendor opposite the door to the tavern, he will have a quest icon (yellow exclamation mark) above his head the first time you visit.


Why Can't I Hold Everything?
Max out your carrying capacity

Simply pick up everything you can until you can't carry any more. If you're having trouble with this, you can keep importing a character from a savegame (pause game -> change players -> import -> choose savegame -> import character) and dropping items until there's enough to max out your carry limit.


What's Yours is Mine
Search through 500 items of loot

This should come naturally if you're opening every chest and breaking every crate/barrel you come across during your first playthrough.


Rest in Peace...Again
You died...again

Just die twice back to back. I loaded a savegame, ran into a group of enemies and died, resurrected and then ran into the same group to die again.


Fear the Feat
Upgrade one feat to Rank 5

All you need to do is upgrade any feat/skill to rank 5 which you will inevitably do during your first playthrough.


Feats Don't Fail Me Now
Upgrade one feat to Rank 5 for each character (not including unlocked characters)

You will need to have one feat/skill at rank 5 with every standard character (excluding the unlockable characters of Drizzt and Artemis).

Note: Since I'm not sure how this is being tracked I played it safe and created 3 savegames with 3 different characters plus the 4th savegame from my first playthrough.
If you have +wisdom gear to increase experience gain, use it and you should be able to hit rank 5 with any skill by the time you finish the sewers quest. Also import your endgame character and drop any gear and high-damage weapons to make this quicker.
Once I had 4 savegames with 4 different characters (each with at least one skill at rank 5) I started a new game with the last missing character, played until I had rank 5 with one skill and the achievement popped.


Maximum Fun
Max level any character

Usually won't be attained during your first playthrough since you need to hit level 40. You can get this during your extreme mode playthrough if you import a previous character or use Drizzt (since he starts at a higher level). If you have items with +wisdom to increase experience gain, this will be faster.

Alternatively:
The cleric, dwarf, monk and necromancer each have sidequests that allow you to pay gold for experience in town (church for cleric, tavern for dwarf and monk, Omduil's manor for necromancer). These quests start out with you paying 2000 gold for 2000 experience and can be done 4 times, each time doubling in price and experience reward. The first quest costs 2000, the second 4000, third 8000 and fourth 16000.
Using two savegames (let's call them A and B) and the character import feature, you can repeat these quests as often as you need. Start with savegame A where you haven't done the quests (or at least not the 16000 gold one) and import character from savegame B. Now do the quest and save the game as savegame B. Load savegame A again and import character from savegame B, spend 16000 gold again, save as savegame B - rinse and repeat.
If you lack gold, simply import a character with high value gear, drop it and sell it as often as you need.


Crafting All Day Long
Create 42 custom items in the Workshop

In order to craft items you will need a base item (no +X prefix) of at least fine quality, i.e. Fine Crossbow (not Crossbow or Shoddy Crossbow!) as well as 1 Rune Stone. You can buy Rune Stones at the vendor in town or find them during your playthrough, gear of fine or better quality can sometimes also be bought from the vendor. When you have the items, go see the vendor in the city of Baldur's Gate and ask to use his workshop, then combine the item and rune stone.
To make things easier, you can use the character import feature to drop the required items without having to buy or find them 42 times, or break the item after crafting it to reuse the base item. To be clear, you don't need to craft 42 different items but can always craft the same one instead (like always crafting a +1 Fine Crossbow).