Accomplish the indicated achievement to get the corresponding number of Gamerscore points:

Mastering the Art (30 points): Earn the INCOGNITO bonus (Multiplayer).
Tools of the Templar (10 points): Purchase your first ABILITY in the Abstergo Store (Multiplayer).
Achiever (10 points): Complete a Challenge (Multiplayer).
True Templar (20 points): Reach level 20 (Multiplayer).
Looking Good (10 points): Customize a PERSONA (Multiplayer).
There Is No I in Team (20 points): Win a session of a team mode (Multiplayer).
Make the Headlines (30 points): Obtain 12 different Accolades (Multiplayer).
The Way I Like It (20 points): Edit your TEMPLAR PROFILE to change your title, emblem, and 
patron (Multiplayer).
Explorer (20 points): Finish a session of each game mode (Multiplayer).
Tactician (30 points): Score at least 2500 points in a session (Multiplayer).
The Early Years (20 points): Complete Desmond Sequence 1.
Best Served Cold (20 points): Complete DNA Sequence 1.
The Reluctant Assassin (20 points): Complete Desmond Sequence 2.
Istanbul and Constantinople (20 points): Complete DNA Sequence 2.
Escape To New York (20 points): Complete Desmond Sequence 3.
Seal the Deal (20 points): Complete DNA Sequence 3.
The Prince (20 points): Complete DNA Sequence 4.
The Plot Thickens (20 points): Complete DNA Sequence 5.
Successes and Failures (20 points): Complete DNA Sequence 6.
The Rotten Apple (20 points): Complete Desmond Sequence 4.
Old Boss, New Boss (20 points): Complete DNA Sequence 7.
Priorities (20 points): Complete DNA Sequence 8.
Are You Desmond Miles? (20 points): Complete Desmond Sequence 5.
Revelations (50 points): Complete DNA Sequence 9.
Fond Memories (20 points): Achieve 100% Synchronization in all Sequences.
Holy Wisdom (20 points): Complete the Hagia Sofia challenge level.
Capped (20 points): Collect all animus data fragments.
Worth A Thousand Words (20 points): Collect all of Ishak Pasha's memoir pages.
Pyromaniac (20 points): Complete all Bomb Missions.
Armchair General (20 points): Control all cities (except Rhodes) simultaneously in the Mediterranian 
Defense game.
Iron Curtain (20 points): Perform a perfect den defense without using the cannon.
Spider Assassin (20 points): Climb Hagia Sofia, from the ground to the pinnacle, in under 25 seconds.
A Friend Indeed (20 points): Complete all Faction Creed Challenges from a single faction.
Tax Evasion (10 points): Get your money back from a Templar tax collector.
The Mentor (20 points): Have seven trainees reach the rank of Master Assassin.
Lightning Strikes (20 points): Kill 5 guards in 5 seconds using only your hidden blades.
Overkiller (20 points): Assassinate 50 guards with the hidden blade.
Show-Off (20 points): Parachute onto a zipline.
Sage (20 points): Collect all available books.
Fast Fingers (20 points): Loot 50 dead guards with thief looting.
Mosh Pit (20 points): Have 10 guards poisoned at the same time.
Mouse Trap (20 points): Kill 5 guards with a scaffold after they have been stunned by caltrops.
Craft Maniac (20 points): Craft 30 bombs.
My Prot?g? (20 points): Have one trainee reach the rank of Master Assassin.
Almost Flying (20 points): Parachute directly from the top of the Galata Tower to the golden horn.
Silent But Deadly (20 points): Kill three guards simultaneously with only throwing knives.
I can see you (20 points): Kill 5 guards while under the cover of a smoke screen bomb.
Monster's Dance (20 points): Have a guard incapacitate 3 civilians while he's poisoned.
Bully (20 points): Find and beat up Duccio.
The following achievements require the "Ancestors Multiplayer Character Pack" bonus downloadable content:
Stopped Dead (20 points): Obtain 3 Hidden Gun kills during a session of Steal The Artifact as 
The Corsair (Multiplayer).
The Vulture (20 points): Perform 5 Ground Finish in Manhunt during a session as The Brigand (Multiplayer).
Pirate's Bravery (30 points): Use the Bodyguard against your pursuer as The Privateer (Multiplayer).
The Juggernaut (20 points): Perform 3 kills using the Charge as The Gladiator (Multiplayer).