There are 50 achievements for Dragon Age 2 and more are available for the DLCs. Below is a complete guide for getting all 50 Achievements for the main game. The DLC achievements are available in the following posts:
Dragon Age 2: The Exiled Prince Achievement Guide
Dragon Age 2: Mark of the Assassin Achievement Guide
Dragon Age 2: Legacy Achievement Guide
The official game guide is also super handy. Pick up a copy from Amazon.

Master Craftsman
Crafted all of the items from a single crafting tree.
There are three different “crafting trees”. You must craft one of every item in one of those trees. You can choose from potions, runes, or bombs and poisons. There are 6 potion recipes, 9 poisons and bombs formulas, or 20 rune designs. To achieve this you must first find the recipe, formula or design, then find the ingredients necessary to create the items. A complete list of all recipes, designs, formulas, and ingredients can be found here.

Mogul
Had 100 or more sovereigns in your purse.
This can be achieved in Act I if you plan carefully. There are many quests and side quests in Act I which you can gain money from by completing. If you complete as many of these as you can, and hold off on investing in the Deep Roads expedition, and only buy the bare essentials, then you can easily have 100 gold sovereigns in your “purse” at one time. If you do fail to get this in Act I, then you just need to save up for it by completing quests and being frugal with your spending.

Crowning Glory
Become the Viscount of Kirkwall.
In the final quest of Act III, “The Final Straw”, you must side with Meredith and the templars if you want to be given the title of “Viscount of Kirkwall”.

Dedicated
Reached Level 10
This is simple enough. Play through the game long enough for your main character to reach Level 10.

A Friend in Need
Upgraded the armour of one of your party members
Throughout the game you cannot equip any of the armour that you find, to any of your party members. You can however, find upgrades for their existing armour. You need to find one of these upgrades for this achievement. If you are struggling to find an upgrade then you can find a complete list of where to find them here.

Enchanter
Enchanted an item
Throughout the game you can buy, or create, runes and attach them to your armour or weapons. To get this achievement you must attach a rune to a piece of equipment. You will need to find an enchanter so they can attach the rune for you. You can find an enchanter in Hightown during Act I or you can speak to Sandal at the Hawke Estate from Act II onwards.

Immigrant
Became a resident of Kirkwall
You will get this achievement when you finish the prologue. You will need to reach Kirkwall and ally yourself with a faction so they will pay for your entrance into the city. When you have been granted access to the city, the achievement will unlock.

Delver of the Deep
Explored the Deep Roads
When you complete Act I and make it out of the Deep Roads, you will automatically get this achievement.

Birthright
Kicked the slavers out of your ancestral mansion
To get this achievement you must complete the “Birthright” companion quest in Act I. For a complete list of quests and how to activate and complete them, check here.

Specialized
Learned two class specializations
Throughout the game you will level your character and gain skills within their specializations. When your main character reaches levels 7 and 14, you will be able to add a new specialization to your character. To add a specialization you need to go to the abilities screen. Here you will see the specializations in the top right hand corner of the screen. Some specializations on the end of the list will be greyed out. Choose one of these and select a skill within this specialization. When you have chosen two specializations, the achievement will unlock.

I Got Your Back
Completely upgraded the armour of one of your party members
Although you can find a lot of armour lying around in the game, and buy even more from merchants, you cannot equip any of these to your companions. To improve their armour you must find upgrades throughout the game. Your surviving sibling can have one upgrade, while all other companions have a maximum of four upgrades. For a complete list of all armour upgrades and where to find them, check here.

Legendary
Reached Level 20
As with the “Dedicated” achievement, you will get this achievement for reaching a level milestone. reach level 20 with your main character and the achievement will unlock.

Financier
Became a partner in the Deep Roads expedition
This quest is story related but can be missed. When you have completed half of the quests in Act I, you will be given a new quest called “Friends in Low Places”. You will be offered the money to invest in the Deep Roads expedition. You must refuse this offer and invest your own money for this achievement.

Talented
Used teamwork to perform a cross-class combo
With each level you gain for your main character, you will be able to choose a skill, or attribute. As soon as you select your first one the achievement will unlock.

Tag Team
Used teamwork to perform a cross-class combo
Cross-class combos are complicated to understand. However, things can be simplified into a couple of key points.
- Cross-class combos are pulled off more frequently if you are a higher level because more abilities have been unlocked.
- A cross-class combo must be setup by hindering an enemy with status affects.
- More importantly than any other point is this. You will unlock this achievement without even trying so you really don’t need to understand cross-class combos.

Weapon Master
Mastered a weapon style
As you gain levels for a character within the game, you will be able to unlock skills and abilities. These skills belong to specialization trees. To get this achievement you must unlock every ability in a single weapon based tree.

Unstoppable
Completed a full year in Kirkwall without any party member being knocked unconscious
Dragon Age II is broken down into three acts. Each Act covers one year of the story. You must complete one of these acts without any of your party being knocked out during combat. The higher the difficulty level that you play on, the harder this achievement will be. The best advice you can have is to stock plenty of potions, heal often, and save often. If someone in your party is knocked out, reload your last save and try again. The use of tactics can be a great help here too. Make sure you have a mage in your party who is set to heal party members whose health drops below a certain threshold. Bear in mind though, their spells will need time to recharge if they have healed someone so watch party members health at all times and heal anyone who is low with a health potion.

Craftsman
Acquired your first crafting recipe
This achievement is practically impossible to miss. You will be given a recipe if you choose to speak to any one of three people in Act I. You can talk to Lady Elegant in Lowtown, who will give you an Elfroot Potion recipe. Tomwise in Darktown will give you Debilitating Potion Formula, and Worthy in Hightown will give you a Protection Rune Design. As soon as you receive any one of these the achievement will unlock.

Dragon Slayer
Found and killed a high dragon
During Act III you can unlock a quest called “Mine Massacre” You can gain this quest by either speaking to Hubert after completing the “Bone Pit” and “Inside Job” quests, or by going directly to the Bone Pit if you did not complete those quests. You will need to kill the High Dragon to complete this quest and unlock this achievement. For more information about this quest, check here. For more information about the quest itself, check here. For more help defeating the dragon, check out this video.

Exorcist
Found and killed the undying Xebenkeck
During Act II you can unlock a quest called “Forbidden Knowledge” How you can gain this quest depends on a decision you made in Act I. If you chose to spare Ildunna’s life during “Enemies Among Us”, a letter detailing the quest will arrive at your estate. If you killed Ildunna then you will need to find an Evil Tome at the Chantry to start the quest. To complete the quest you will need to find and destroy 5 evil tomes. The location of these tomes can be found here. If you want some more help defeating the Xebenkeck, check out this video.

Demon Slayer
Found and killed the ancient demon, Hybris
This is another optional quest you can undertake during Act III. To acquire the quest you will need to find 3 Awiergan scrolls. The location of these scrolls can be found here. When you have found all When you find each scroll you will need to complete certain steps because each scroll is a quest in itself. The details of these steps can be found here. When all three scroll quest are complete you will unlock a new quest called “Awiergan Scrolls: Pride Unbound”. You must complete this quest to find the demon, Hybris, and kill him. If you need some help defeating the demon, check out this video.

Chantry Historian
Found all four chapters of “The History of the Chantry,” by Brother Genitivi
The description of this achievement is pretty accurate. You must find all four chapters of Brother Gentivi’s History of the Chantry, all of which are found in the Chantry itself. Although all of these codex entries are missable, three of them are available for a sustained length of time. However, one of these entries will only be available for the duration of one quest. Chapters 1,2 and 4 can be gained during the 3 acts. So, chapter 1 would be available for the duration of Act I and so on. Chapter 3 will only be available during the “Following the Qun” quest in Act II. If you miss any of these entries you will not be able to get the achievement. For specific locations of the codex entries, check here.
A Worthy Rival
Earned the Arishok’s respect
This achievement must be unlocked before you complete the “Demands of the Qun” quest. To gain his respect you must abide by the rules of the Qun. To do this you need to always be honest with him by picking the green leaf option in the conversation wheel. There are other things you can do which will affect how the Arishok sees you. These steps are outlined below.
When you are given the quest “Offered and Lost”, go and speak to the Arishok about it and tell him that his “delegate is missing”.
During “Offered and Lost”, when you speak to Viscount Dumar, encourage him to tell the Arishok the truth.
When you complete “Offered and Lost” go back and talk to the Arishok again and be honest in everything you tell him.
During “Demands of the Qun”, when talking to the Arishok about the relic, be sure to tell him that Isabela has it.
For more information about these quests, check here.

Great Minds Think Alike
Earned the friendship or rivalry of four party members
The decisions you make and the conversations you have with you companions, will affect the relationship you have with them. If you make decisions that your companions approve of and speak to them in a way they agree with, then you will earn a friendship with them. If however, you make decisions that go against their principles and you are mean to them, then they will become your rival. You need to earn 100% friendship or rivalry with four companions for this achievement. Note: If you make sure you have at least one friend and one rival then you will be able to get the “Friend” and “Rival” achievements at the same time. Information about companions and how to develop relationships with them can be found here.

Friend
Earned the friendship of one of your party members
See “Great Minds Think Alike”

Rival
Earned the rivalry of one of your party members
See “Great Minds Think Alike”

Romantic
Completed a romance with one of your party members
To complete a romance with a companion you will need to know what makes them tick. to have a relationship with a character you need to make decisions that they will agree with and don’t say anything to them that they won’t like. Complete their companion quests and flirt with them whenever you can. When their friendship is high enough they will visit your estate if you go there at night. Here you have the chance to be intimate with them, and if you play your cards right, you can ask them to move in with you. For more information about romance and how to achieve it with you companions, check here.

Epic
Completed Dragon Age II twice, or completed it once with a save imported from Dragon Age Origins
If you did not play, or do not have the save files for, Dragon Age Origins, then you will need to play through the game twice in it’s entirety. If you do have save files from Dragon Age Origins, when you go through the character creation during the prologue, you will be able to import one of your save files rather than use a preset history. If you do this then you will only need to complete Dragon Age II once for this achievement.

Champion of Kirkwall
Completed Dragon Age II
This achievement is story related and cannot be missed. It will unlock when you complete the game.

Mercenary
Allied yourself with the mercenaries upon arriving in Kirkwall
When you first arrive at Kirkwall, you will need to find a way to earn your way into the city. There are two factions that agree to help you if you can prove yourself to them. To gain this achievement you will need to speak to Meeran and agree to carry out the task he sets for you. For more information about this quest you can check here.

Nefarious
Allied yourself with the smugglers upon arriving in Kirkwall
Upon arrival at Kirkwall you will need to find a way into the city. The smugglers will help you if you agree to work for them. If you decide to accept their help then you need to talk to Athenril and do what is asked of you to get this achievement.

Flirtatious
Flirted with one of your party members to begin a romance
This is easily achieved so long as everybody in your party doesn’t hate you. Having everyone hate you would be one hell of an achievement in itself. You need to gain enough friendship with a companion so you are given the option to flirt with them while you talk. When you are talking to a companion, choose the option on the dialogue wheel with a heart. This is you flirting and will unlock the achievement. For more information about the companions and how to romance with them, check here.

Mass Exodus
Reached Kirkwall with each character class across multiple playthroughs
Although tedious, this achievement can be gotten in a reasonably short amount of time. You will need to play through the game long enough to get to Kirkwall. You do not need to gain entry into the city but you at least need to get to the city gates. Do this for each of the three classes and the achievement will unlock.

Knowledgeable
Unlocked 100 codex entries
Throughout the game there are many sources of information lying around. You can look at books, leaflets and random pieces of paper and you will gain a codex entry. Do this 100 times and you will get the achievement. It might sound like a lot but it really isn’t too bad.

Treasure Hunter
Opened 50 chests
Throughout the game there are many chests that you can open. Some are locked and will require a Rogue with high a enough cunning attribute to open them. Open 50 chests for the achievement.

Darkness Falls
Toggled the map from day to night
This is the easiest achievement to get in the whole game. When you open the map for the first time, press the right or left triggers until the map is displaying available night time quests. This will unlock the achievement.

Explorer
Left Kirkwall to explore the outlying regions
This will happen as you play and will require no effort on your part. Eventually you will have to leave the city to carry out some business. This will unlock the achievement.

Spelunker
Visited 10 caves in Kirkwall and the surrounding area
This is another achievement that will unlock in time as you play. To ensure you unlock it, it is best to accept every quest you can that will take you into caves and you will get the achievement. A full list of quests and their details can be found here.

Full House
Recruited four party members
There are 6 companions that you can recruit to your party during Act I, not including the sibling that you start with (7 if you have the DLC). You must recruit any four of these companions for this achievement. The companions you can recruit are:
- Varric (recruited as part of the story)
- Aveline (recruited as part of the story)
- Anders (recruited when you complete Tranquility)
- Merrill (recruited when you complete Long Way Home)
- Isabela (recruited when you complete Fools Rush In)
- Fenris (recruited when you complete Bait and Switch)
- Sebastian (DLC only, recruited when you complete Duty)
More information about your companions can be found here.

Friends in High Places
Met Grand Cleric Elthina, Viscount Dumar, Knight-Commander Meredith, and First Enchanter Orsino
This achievement is story related and cannot be missed. It will unlock as you play through the “Demands of the Qun” quest.

Gift Giver
Gave a gift to one of your party members
While you are playing you can find gifts for your companions. The gifts you can find are not like regular items. There are specific gifts for specific companions. When you have one in your possession, go and talk to the companion it is intended for to give it to them. A list of the gifts available and where to find them can be found here.

Supplier
Found every variety of crafting resources
Throughout the game you can find ingredients needed for crafting.
There are 12 varieties of ingredients and as usual, they are only available during the Act that they appear in. For example, if you there is a deathroot in Darktown in Act I and you don’t collect it before the end of the Act, then you will not be able to get this achievement.
Three of the ingredients are more missable than others. Ambrosia can only be gained if you meet a specific set of requirements. You can only get this ingredient from Isabela during Act II. To ensure that she is still in your party you must ensure a high friendship with her before you start the quest “Demands of the Qun”. Above all else, do not hand her to the Arishok during this quest or you will lose her from your party and will not be able to get this ingredient. (Further information about Isabela can be found in the Companion Guide)
Felandaris can only be found during the “Pride’s End” quest, and Dragon’s Blood must be taken form the High Dragon in “Mine Massacre” If you have missed something, and you have access to the Black Emporium, you can go there and buy an ingredient that you have missed in the Act before, but I am not sure if this is true for every ingredient.
For more information about where to find all the other ingredients, check here.

Archeologist
During each year in Kirkwall, discovered 3 secret messages from the Band of Three
For each act in the game, there are 4 Messages from the Band of Three lying around. You must three from each act to get this achievement. When you are wandering around, these messages will show up as “The Enigma in Kirkwall” and will look like a codex entry. For information about where all 12 of the messages are, check here.

Tale Within a Tale
Listened to Varric begin his tale of the Champion of Kirkwall
This will unlock when you kill the Ogre during the prologue of the game.

Stone Cold
Defeated the rock wraith on your expedition into the Deep Roads
This achievement will automatically unlock when you defeat the Rock Wraith at the end of Act I.

King of the Hill
Defeated the Arishok
Although the opportunity for this achievement is story related, if you don’t handle the situation correctly, you can miss it. To get this achievement you must fight the Arishok, either alone or with your companions. If you chose to hand Isabela to the Arishok, you will not need to fight him and you will not get the achievement. For any help defeating the Arishok, check out this video.

Conqueror
Defeated Meredith, knight-commander of Kirkwall’s templars
Whether you chose to side with the templars or the mages, at some point you will have to fight Meredith, making this an unmissable achievement.

Arcane Defender
Sided with the mages five times
Throughout the story you will have several opportunities where you will have to side with the mages or the templars. To get this achievement you will need to side with the mages in 5 of these quests. The quests that you can chose form are Wayward Son, Act of Mercy, Enemies Among Us, Night Terrors, Best Served Cold, On the Loose and Showdown. For more information about these quests you can check here.

Mage Hunter
Sided with the templars five times
This achievement is the same as “Arcane Defender” but you need to side with the templars instead of the mages.