The so-called Accolades are rewards you get after you finish up a session. Collect 13 different rewards to unlock this achievement.
This achievement will come with normal gameplay too. You don't really need to boost it.
This DOES NOT has to be done in one session, you can spread it out (Thanks to DiQn3 over at TrueAchievements.com for mentioning it)
I will mention all accolades that you can possibly earn below:
- Assassination
Had the best kill/death ratio - The Professional
Had the most contested kills - The Savage
Had the best single kill score - The Expert
Was the first to die - The Sacrificial Lamb
Died the least - The Survivor
Died the most - The Target
Had the highest score - The Champion
Had the most kills - The Slayer
Was never killed - The Untouchable
- Abilities
Performed the most Animus hacks - The Hacker
Used the greatest variety of abilities - The Improviser
Poisoned the most targets - The Poisoner
Was disguised or morphed longest - The Undercover
Had the most hidden gun kills - The Sniper
Spent the most time affected by abilities - The Victim
- Style
Stayed alive longest - The Immortal
Spent the most time walking - The Wanderer
Earned the most focus bonuses - The Stalker
Earned the most assist bonuses - The Wingman
Earned the most incognito bonuses - The Master
Performed the most ground finishes - The Vicious
Spent the most time on rooftops - The Gargoyle
Had the greatest approach bonuses - The Invisible
Made the most escapes - The Escape Artist
Finished first, second, or third - The Achiever
Was stunned the most often - The Drunkard
Performed the most stuns - The Stunner
- Modes
Revived the most allies - The Savior
Was on the winning team - The Dependable
Won a free-for-all - The Lone Wolf
Was acquired the least - The Elusive
Killed the least civilians - The Wise
Survived the longest as Uncorrupted - The Saint
Stole the most artifacts - The Thief
Had the best streak - The Machine
Killed the most targets near chests - The Watchdog
Captured the most chests - The Robber
Killed the most pursuers near VIPs - The Protector
Killed the most VIPs - The Agitator
Dropped the most artifacts - The Clumsy
Scored the most artifacts - The Glutton
Killed the most artifact thieves - The Stalwart
Made the most kills without being stunned - The Practiced
Spent the most time blended with an ally - The Lurker
Note: You can also check how many you have unlocked by going to the Data Hub by pressing LB, then selecting Templar Profile, and checking Accolades. (credit to RabidDolphin87 over at TrueAchievements.com)