You will receive these achievements for simply playing the game.

First Blood

Perform Your First Combat Execution.



Time to Fly

Perform Your First Environmental Execution.



To Protect And To Serve

Meet Nero.



Give Caesar What Is His

Purchase And Use An Upgrade In Combat.



I Have A Story To Tell

Complete The Beginning On Any Difficulty.



Forever Lost

Find Your Mother And Sister.



I Will Avenge You, Father

Complete S.P.Q.R. On Any Difficulty.



Saving Private Marius

Complete Trial By Fire On Any Difficulty.



Who's That Girl

Meet Boudica.



Trouble In Sherwood Forest

Complete The King On Any Difficulty.



The Bigger They Are ...

Defeat Glott.



Heart Of Darkness

Complete Edge Of The World On Any Difficulty.



Inner Demons

Find Out What Really Happened To Your Parents.



Siege Me If You Can

Complete Pax Romanum On Any Difficulty.



From The Dead

Become The Righteous Hand Of Vengeance.



Never Give Up, Never Surrender

Defeat Commodus.



Ave, Caesar

Complete The Wrath Of Nemesis On Any Difficulty.



Not My Type After All

Defeat Boudica.



Settling Old Debts

Complete The Son Of Rome On Any Difficulty.

Veni, Vidi, Vici

Complete The Game on Any Difficulty.



My Empire Of Dirt

Complete The Game On Soldier Difficulty.



Bad To The Bone

Complete The Game On Centurion Difficulty.



These achievements stack, so by playing on Centurion difficulty you will get all three by the end of story mode.


When it comes to Legendary difficulty, it is unavailable at the start of the game. You need to complete all chapters on Centurion to unlock it.

Enemies hit harder, you have less HP regen, you need to do perfect executions, the timing for parries is very precise, and there are no red glowing indicators for evading heavy attacks. Thankfully, you don't restart the whole chapter when you die, just from the recent checkpoint.

Some people report that they do not get achievements for completing levels when starting a New Game. If that's your case, pick chapter one from the chapter selection screen and select Legendary.


I Have A Story To Tell (Legendary)

Complete The Beginning On Legendary Difficulty.





I Will Avenge You, Father (Legendary)

Complete S.P.Q.R. On Legendary Difficulty.





Saving Private Marius (Legendary)

Complete Trial By Fire On Legendary Difficulty.





Trouble In Sherwood Forest (Legendary)

Complete The King On Legendary Difficulty.





Heart Of Darkness (Legendary)

Complete Edge Of The World Legendary Any Difficulty.





Siege Me If You Can (Legendary)

Complete Pax Romanum On Legendary Difficulty.





Ave, Caesar (Legendary)

Complete The Wrath of Nemesis On Legendary Difficulty.





Settling Old Debts (Legendary)

Complete The Son Of Rome On Legendary Difficulty.

Head Executioner

Perform 100 Executions In Any Game Mode.



Self-explanatory.


Comboing My Way Through

Defeat 10 Enemies In A Row Without Sustaining Any Damage.



Monstrum Combo

Defeat 25 Enemies In A Row Without Sustaining Damage.



These can be done in either the story mode on any difficulty or in a multiplayer match.



Double-Down

Perform 50 Double Executions In Any Game Mode.



You need to put two enemies in execution range (skull above their heads) before you press RT.


Medium Rare

Use An Execution To Set Fire To An Enemy.



Execute an enemy near a fire and you should get the unique interaction. I personally unlocked this by accident in chapter six shortly after the defence on the walls.





Here is another way to get this in chapter five:


Step Right This Way!

Use A Trap To Kill An Enemy.



This can be done in either single player or multiplayer, but multiplayer is the easier way. Wait for an enemy to get near a spiked trap, set it off and hope the enemy dies from it.




Been There, Done That

Replay Any Single Player Level.



Simply go into chapter select, pick any chapter you have already finished and when the level loads, the achievement will pop.


There's No Such Thing As Luck

Kill An Enemy By Perfectly Deflecting An Arrow.



You can get it as early as chapter three when the game teaches you about deflecting. Just stand still and spam deflect until the achievement unlocks.





Marketer

Get In Combat With All Executions And Upgrades Purchased.



You need all Hero and Execution upgrades. Replay chapters, use the xp gain bonus for executions and get a high multiplier to get the most points the fastest. All upgrades unlock for purchase by level 7 and you'll need 2 million valor for everything. When you do unlock everything, load up any chapter and the achievement should unlock.

Letters From The Front

Collect One Scroll.



The first scroll in the game is in chapter one. After learning about executions, you will climb up a wooden scaffolding. Simply turn left and the corpse will hold the scroll.





Roman Tourist

Collect Your First Vista.



The first vista is in chapter one. After holding off the barbarian attack, but before entering the palace, look left and there will be a shield with your first vista.





Something I Found On The Way To The Forum

Collect One Chronicle.



The first chronicle is in chapter one. Before you open the door for Nero, look behind you and to your right there will be your first chronicle.





Avid Reader

Complete A Comic Book By Collecting 6 Chronicles In A Level.



Pick up all chronicles in any chapter (outside of one and two). If you're hunting for collectables, this should unlock on its own.


Ancient Scholar

Collect All The Scrolls.



Photo Album

Collect All The Vistas.



Finders Keepers

Collect All The Chronicles.



There are a total of 90 collectables in the game: 27 scrolls, 21 vistas, 42 chronicles.

User Nugorra pointed out about the numer of chronicles in the game:

Everybody wonder about the 42 chronicles, when ingame you see 51.
Level 1(3) each chronicle counts for 3, and level 2(3) each count for 2.
Soooo, it's 42 chronicle locations, you get the remaining 9 from Level 1 and 2.

Colosseum Recruit

Complete Your First Multiplayer Campaign.



Colosseum Veteran

Complete 20 Multiplayer Campaigns.



Campaign = match. Play coop or solo multiplayer games, win or lose you will get these achievements.


Bloody Centurion

Defeat 100 Enemies In Multiplayer.



Trueblood

Perform 1000 Executions In Multiplayer.



Self-explanatory.


Brothers In Arms

Perform A Co-op Execution.



Either play a match with a random player or a friend. Simply press the execution button at the same time as your coop partner. With randoms it can be tricky, but it's fairly doable.


It's Just A Flesh Wound

Revive Another Player 3 Times.



When your coop partner goes down, stand next to them and press A. Doesn't have to be done in a single match.


Grace Of The Gods

Unlock The First Reward Of The Gods.



Champion Of The Gods

Unlock All The Rewards Of The Gods.



When you start a multiplayer game you will pick a god that gives you various bonuses. Once you play enough rounds with the same god (doesn't have to be in a row), you'll unlock your reward. You can check your progress by looking at the red bar under the "Reward:" icon. When you unlock one reward, pick another god and repeat this until you've unlocked all four.





Simply The Best

Achieve Rank 100 In Multiplayer.



Best Of The Best

Achieve Rank 150 In Multiplayer.



Master Of The Colosseum

Achieve Rank 200 In Multiplayer.



Start grinding. Here's some help:



Colosseum Warrior

Fight On Each Multiplayer Arena Environment.



You need to play on each of the eleven base game maps. The problem is that you can only play a few of them solo, so you will have to play Arena mode. The quickest way to play all the maps are these Arena playlists:

Defense of Rome
Teamwork
World Tour
The Frontier
Endless Hordes

Go into Custom Match, Arena, pick your playlist and then "Match me" to find a partner. Or play with a friend.


We'll Never Survive

Play A Round Of Survival Mode.



Self-explanatory.


Survivor

Play A Round Of Survival On Island.



Go into Custom Match, Survival, pick Island and then "Match me" to find a partner. Or play with a friend.


Oh, Let Me Have A Little Bit Of Peril?

Survive For 7 Minutes In Dockyard (Survival Mode).



You Were In Terrible Peril

Survive For 7 Minutes In Courtyard (Survival Mode).



No, It's Too Perilous

Survive For 7 Minutes In Firestorm (Survival Mode).



Go into Custom Match, Survival, pick Dockyard/Courtyard/Firestorm and then "Match me" to find a partner. Or play with a friend. Survive for at least seven minutes, after that you can die and the achievement will unlock.


This Is My Island

Perform 30 Environmental Executions On Island.



A Walk In The Park

Perform 30 Environmental Executions In Forbidden Forest.



Do these in Survival mode. On Island use executions near the water, and on Forbidden Forest near the spiked wall to send the enemies flying for an enviromental kill. Doesn't have to be done in a single match.






Uh, He's Already Got One, You See

Complete Barbarous.



Mmmm, Beacon

Complete Beacon.



You Shall Put No Other Gods Before Me!

Complete False Gods.



Build A Bridge Out Of Her

Complete Invictus.



Open the multiplayer tab, go to Custom Match, Solo, then pick your map. You need to win for the achievements to unlock.


Only The Finest

Equip Your First Rare Item In Multiplayer.



Get 400 coins from playing multiplayer, buy a silver booster pack for a guaranteed rare item and then equip it. Go into a multiplayer match and the achievement should unlock then.


Say Hello To My Little Friend!

Equip Your First Tier 2 Item In Multiplayer.



Son Of Vulcan

Equip Your First Tier 5 Item In Multiplayer.



Big Bling

Equip Your First Tier 6 Item In Multiplayer.



You must buy corresponding tier booster packs to get the necessary items. The achievement booster packs require you to be Rank 5/90/130, respectively. Once you equip your item, go into a multiplayer match and your achievement should unlock.

Thanks to 360GameTV for the fantastic Legendary walkthrough as well as for the detailed collectables video.

Thanks to EnemyBritBomber, FearedAngel, Guides trophées vidéos (par nemesis1385) and NiightDJ for the great achievement videos.

Thanks to Markyshizzle for the rather necessary guide for quick XP leveling in multiplayer.

Thanks to Nugorra for a note about the collectibles.

Please leave a comment if you found any errors in this guide, I'll try to fix it ASAP.

Also leaving a like if the guide helped you would be greatly appreciated. :)