Full list of all 54 The First Templar achievements worth 1,250 gamerscore. It takes around 20-25 hours to unlock all of the achievements in the base game.
The base game contains 48 achievements worth 1,000 Gamerscore, and there is 1 DLC pack containing 6 achievements worth 250 Gamerscore.
Rescue the messenger of King Philip
Defeat the beast
Rescue Marie d'Ibelin
Survive the siege of Acre
Defeat Muzafar
Explore the Temple of the Nine
Survive the events of Friday the 13th
Find the Grail
Complete all levels on Casual or higher difficulty
Complete all levels on Normal or higher difficulty
Complete all levels on Hard difficulty
Discover a clue
Discover all chests in a single level
Complete all Bonus Objectives in a single level
Complete all Bonus Objectives on all levels
Collect all Templar Chronicles
Find all collectible outfits in the game
Find all collectible weapons in the game
Advance a character to 5 Health Orbs
Advance a character to 5 Zeal Orbs
Use the "Revive" action to help your teammate
Disarm a bear trap
Save your partner from a dog attack
Destroy a breakable wall
Distract and then stealth kill an enemy
Kill an enemy by knocking him from a ledge
Win a duel
Finish a whole level without both characters dropping below 1 Health Orb
Smash 5 enemy shields
Finish off 30 fallen enemies
Succesfully perform 10 countermoves
Successfully track 20 trails to their end
Kill 20 enemies with a ranged attack
Set 50 objects on fire
Perform 50 stealth kills
Kill 5 enemies in less than a minute without taking damage
Kill an enemy grabbed by the other character
Kill all opposing squads with a siege weapon
A fleeing enemy is killed with a siege weapon by you or your partner
Heal your partner using the Mass Prayer skill
Acquire all Charge skills for Celian
Acquire all Dagger throw skills for Marie
Hit 4 enemies with your charge attack at the same time
Hit 4 enemies at the same time with your All-around Attack.
Play an online multiplayer game with one of you Xbox LIVE friends
Finish a level in an online multiplayer game
Finish all levels in the campaign in multiplayer online mode
Complete 5 levels in online multiplayer with different partners
Complete the Arena
Complete all Bonus Objectives in the Arena
Kill 15 opponents in the Arena using Cyclone Strike.
Complete the first round in the Arena without taking damage
Complete the second round in the Arena without taking damage
Complete the third round in the Arena without taking damage