Dragon Age 2 is a massive game, with hundreds of different spells and talents to learn. Use the guide below to help you decide what combination will best suit your play style.
Warrior Abilities
Weapons and Shield
Hawke, Aveline, Carver
Should first and foremost be used if you want to be a Tank. For example, Shield Defense lowers your damage by 25 percent, yet boosts your capacity to withstand blows. Along with that, Perception and Safeguard make you immune to flanking and critical hits. I highly suggest picking these up as soon as possible.
You should also look into picking up Shield Bash and Pummel as they are invaluable in large groups of enemies. If you want to do some serious damage as a Tank, acquire Scatter and Assault.
Two-Handed
Hawke, Fenris, Carver
If you are the two-handed weapon type of player, gain Giant's Reach, Mighty Blow, and Scythe immediately. This is definitely the stat tree you'll want to upgrade if you are the type of player that likes to do a ton of damage.
Vanguard
Hawke, Aveline, Fenris, Carver
If you want to boost your attack abilities, Vanguard is for you. With abilities such as Might and Control, you are able to boost your attack and/or damage by 10 percent. This isn't an incredibly high percentage increase, so be careful when picking these abilities up. You'll need to use them with a strict strategy (generally a DPS type of player) if you want to see their true potential.
The best combination I have found is to have a Mage cast Hex of Torment on a target, then unleash a wave of attacks from a warrior with Might, Destroyer, and Cleave. This will decimate your enemies incredibly quickly.
Battlemaster
Hawke, Aveline, Fenris, Carver
This is mainly used to maintain or replenish stamina. If you are playing as a Warrior I highly picking this up - if you are playing as a Tank I wouldn't recommend it.
Pick up Rally as soon as you can, as it allows a Warrior to share the effects of his/her sustained talents with the rest of the party. You can extend this by purchasing the Unite upgrade as well.
Defender
Hawke, Aveline, Fenris, Carver
Look for this if you want to be a Tank as it gives you the ability to take a lot of hits (hence the term Defender I suppose). Turn the Blade offers bonuses to Defense and Fortitude, while Elemental Aegis boosts your elemental resistances.
Make sure to pick up the two previously mentioned talents if you want to be a Tank. Also not a bad idea to level up Resilience as it offers 100 percent knockback resistance.
Warmonger
Hawke, Aveline, Fenris, Carver
Purchase both Pommel Strike and Pommel Blow as quickly as possible. These will leave your opponent staggered, opening them up for an intense array of attacks from you and your team. This is a great stat tree for any kind of warrior.
If you want to be a Tank, pick up Taunt, Bravery, and the rest of the abilities that follow. Getting your enemy to notice and attack you is key if you are going to rule the land as a Tank.
Guardian
Aveline
Get rid of Immovable. It's completely useless and tends to leave Aveline in a lot of sticky situations. Make sure to use Bodyguard, Indomitable Skin, and Thick Skin if you want any chance at conquering the harder difficulties. They will make it almost impossible to damage you for a period of time.
Tevinter Fugitive
Fenris
Fenris is a DPS-character by definition. Veneer of Calm is great to use when Fenris is low on health as it will increase the damage given.
Templar
Hawke
Make sure to use this if you are going to use Hawke as a DPS type of character. The main reason is because Cleanse, Silence, and Righteous Strike are all used to impair your enemies offensive capabilities. Also, don't forget about Holy Smite, which is incredibly damaging against Fade enemies.
Reaver
Hawke
Make sure to get Blood Frenzy and Sacrificial Frenzy, as they increase the damage output the lower your health becomes. The activated (rather than passive) ability can even double the increase.
Devour is by far my favorite ability, especially when upgraded. This allows Hawke to both damage and gain health at the same rate, leaving you essentially invincible. If you have Sacrificial Frenzy, you'll be set for the entire game.
Berserker
Hawke
More stamina is more power, plain and simple (at least when it comes to this skill tree). The majority of these stats are going to last for a small amount of time, so keep this in mind when upgrading it.
Rogue Abilities
Dual Weapons
Hawke, Isabela
You'll want to attain every talent in this tree. It's going to be by far your most important one. If you are looking for heavy, single-targeting damage, make sure to get Unforgiving Chain and Explosive Strike. You can hit your opponent ten times to stun them, then hit them with Explosive Strike to unleash intense damage.
Backstab and Twin Fangs are key to your success as well. If you can use Backstab on a stunned opponent, you will be able to kill them immediately. You can also combo this with an ice attack to watch your opponent shatter into a thousand-bajillion pieces (trust me, the number is accurate - I had a nerd count them).
Archery
Hawke, Varric, Sebastian
If you decide to go for Archery, this is obviously an important tree. Make sure to pick up Bursting Arrow and Archer's Lance. These will help you take on large groups of enemies, especially if they have been frozen. Along with that, Pining Shot will stun an enemy, allowing ample time to unleash some fierce magic and get a cross-class combination going.
If you are looking to contain a large group of enemies, Hail of Arrows is a great choice. While it isn't the highest damaging attack out there, it's one of the best Area of Effect skills you're going to find.
Sabotage
Hawke, Varric, Sebastian, Isabela
I am not a fan of this stat tree, as it has absolutely no skills that deliver direct damage. It's great for a supporting character, but I would rather have said supporting character be my healer. If you still want this, your best options are going to be Rush, Miasmic Flask, Fatiguing Fog, and Confusion.
Subterfuge
Hawke, Varric, Isabela, Sebastian
Make sure to pick up Stealth, and Ambush if you are going to stick with this tree. They will allow your character the ability to go invisible for a short while, giving you a great chance of sneaking up on your enemies. You can use Stealth greatly to your advantage by setting up rear attacks and enchanted weapons.
Subtlety is a lot of fun to use, as it gives you a 25 percent threat reduction, benefiting both you and your team. Evade is also very necessary, as it will let you... evade.
Specialist
Hawke, Varric, Isabela, Sebastian
I would suggest only using this tree on Varric, as it's very complicated and requires spending a lot of points to get where you want to be. You should start by picking up Speed (with Harmony). After this, grab Well-Oiled and Bianca's Song. These two combined carry a lot of firepower, especially when coupled with Varric's weapons.
Scoundrel
Hawke,Varric, Isabela, Sebastian
If you decide on this tree, Blindside and Twist the Knife are incredible passive abilities. The former gives you the ability to boost damage against enemies engaging other allies, and the latter promises to give critical hits against stunned opponents.
Along with that, there is Back to Back which should be used mainly to help out a weak ally. It will teleport you to said in-need-of-aide-ally, and also lets you upgrade to Brand and Follow-Through. With Brand, make sure to use it against single opponents to see it's true potential. It's not great in large groups of enemies.
Swashbuckler
Isabela
I wouldn't recommend this stat tree, unless you are looking to decrease a great enemies defenses. If that's the case, which it normally is during higher level playthroughs, make sure to pick up Below the Waterline as it will decrease an enemy's defense by 50 percent for 20 seconds.
If you want to take unleash some serious damage, look for All Hands on Deck. Other than that, there really isn't much going on.
Marksman
Varric
This is a terrific stat tree for Verric - though it requires you spend quite a few points. You'll have to first unlock Rhyming Triplet in order to get Well-Oiled, Bianca's Song, and Embellishment. Make sure to pick these up early in the game - the damage they create is absolutely insane.
Royal Archer
Sebastian
This stat tree has by far one of my favorite skills in Guardian Angel. What happens here is a decoy that will take the pressure of you as long as you are hidden. The best way to use this (from what I can tell) is to distract larger enemies while you pick off their weaker goons.
Holy Precision, Maferath's Advance, and Disciple's Discipline are the main reasons for this stat tree however, as they are all passive abilities that boost your character a lot.
I would stay away from Wounding Arrow and Righteous Chain as they will require at least ten consecutive attacks to use, and unless you do this manually simply won't happen. Being that this is for Sebastian, the chances of you taking the time to do these manually is slim to none.
Assassin
Hawke
If you are having troubles with single enemies, upgrade the Mark of Death as it decreases an enemy's resistance by 50 percent for 20 seconds.
If you are looking to deal some serious critical damage, buy Pinpoint Strikes (100 percent critical) and couple it with Bloodlust (regen stamina per kill) and Devious Harm (plus one percent crit damage per point of Cunning). If you are able to do this, you will basically not stop hitting for critical hits until the spell ends. It's amazing.
The last thing you should get here is Assassin as it will take of a ton of points. If you use it against Brittle enemies it will damage them even more, leaving a lot of them at one-hit kills.
Shadow
Hawke
This is a specialization that I can't imagine playing without. Right off the bat you need to pick up Pinpoint Precision (25 percent passive boost to critical damage). If you thought your crit hits were massive before, you ain't seen nothin' yet.
After this, Disorienting Criticals will increase your critical damage by 25 percent, and has a 100 percent chance of leaving your enemies disoriented. If you really want to get serious, get Shadow Veil, go into stealth, then launch Explosive Strike, Archer's Lance, or Assassinate (cross-class combinations). The 100 percent automatic critical will disorient the enemy, always leaving them open to cross-class combos.
Much like Guardian Angel, Decoy will summon a decoy. Obviously. However, there are two upgrades here that will level up your little decoy buddy that Guardian Angel doesn't have.
Once again, highly recommend this stat tree.
Duelist
Hawke
If you want to be a Tank, this is a good specialization for one reason: Throw the Gauntlet. This will make a single enemy abandon whomever they are attacking and chase after Hawke. On top of that, said enemy will have penalties added to their damage and defense while attacking Hawke. Throw in Parry and Riposte and suddenly Hawke's defenses are raised while his enemies defenses are being lowered.
If you can stagger your enemy, Vendetta is in the top three most powerful attacks in the game for single-targets. I've actually yet to see an attack yield a better result, and for that I believe Duelist is a key specialization to master.
Mage Abilities
Elemental
Hawke, Merrill, Anders, Bethany
This is going to be the skill tree for those out there who want to deal a lot of damage. Along with that, Cone of Cold, Winter's Grasp, and Firestorm are three of the best Area of Effect spells in the game. Make sure to get this if you choose this skill tree as they are incredibly powerful. Also, don't forget Elemental Mastery, as it will strongly increase your spells.
Primal
Hawke, Merrill, Bethany
The spell Tempest is huge as it doesn't deliver friendly fire damage during Nightmare difficulty. If you are playing on this difficulty, this spell is a must. You should also invest in Rock Armor as it's inexpensive and will increase your defense greatly. Look to upgrade this if you are wanting to build a Mage that is heavy on Magic and Willpower.
Stonefist and Chain Lightning are incredibly devastating when used with cross-class combos, so if you are trying to be a veteran of the game these are going to be a necessity.
Spirit
Hawke, Anders, Merrill, Bethany
If you are fighting with a Rogue, make sure to upgrade Spirit Bolt as it's twice as effective against disoriented enemies. Also, make sure to fully upgrade Walking Bomb, as it's incredibly powerful against hordes of enemies.
If you are playing on some of the higher difficulties, seriously consider Dispel Magic as it will keep the higher ranked mages at bay much longer.
Arcane
Hawke, Anders, Merrill, Bethany
This is the "support healer" if there ever was one. For this, make sure to get Elemental Weapons and Arcane Shield. In all honesty, I think that Mind Blast is a waste of points, but it can be of great use if you are trying to distract an enemy.
Easily one of the most powerful single-target spells in the game is found in this tree. It's known as Crushing Prison and can cause some serious damage.
Entropy
Hawke, Merrill, Bethany
I would stay away from this tree unless you are playing on Nightmare. It doesn't have any great area spells, and tends to simply waste your magic. Due to this, Horror and Hex of Torment are the only worthwhile spells when playing Normal or lower.
Creation
Hawke, Anders, Bethany
If you are playing as a Mage this is completely necessary. Make sure to equip Heal as it's going to save your life more than once. Along with this, Glyph of Paralysis and Glyph of Repulsion are great for taking on stronger enemies and strategic instances respectively. For example, you can use Glyph of Repulsion to stop an enemy from entering a doorway, or cast it on a weak party member to give them a force field.
Vengeance
Anders
You'll have to get Panacea and Vengeance as they are the only routes you can go. Once here, use Aid Allies and Regroup to heal and revive respectively. Be careful here as they have serious damaging effects to overall mana, with 40 percent of it being penalized. Try monitoring these manually as to not find yourself in a bind.
Dalish Pariah
Merrill
Be careful with Blood of the First as it consumes health rather than mana to cast the spell. This can be somewhat countered however by gaining her friendship (and getting the Solidarity bonus), and/or with Wrath of the Elvhen (which is constant nature damage).
If you are hell-bent on this stat tree, make sure to dump a lot of points into Constitution as you are going to need a lot of health (due to the health being taken instead of mana).
Force Mage
Hawke
This stat tree is great to immediately increase your physical and elemental force. Pick up Unshakable (a passive ability) that will give you +100 to Fortitude. If you are going to pick up Fist of the Maker, it's absolutely critical that you upgrade it. Without upgrading it's very weak, but adding in Maker's Hammer and Maker's Fury, you can get a bonus of 900 percent damage. That's a huge bonus that no one should let slip by.
Spirit Healer
Hawke
This stat tree is mainly used to keep your crew healthy. Keep in mind that while Healing Aura is active, you will be open to attacks, while being limited offensively. You'll absolutely want to pick up Vitality and Second Chance as they will give you a +10 boost to constitution, a +100 boost to health regen, and the ability to rid of injury management respectively.
Blood Mage
Hawke
This is a great stat tree as long as you plan ahead. It requires a lot of points to get the whole shabang out of it, so using points all willy-nilly won't get you anywhere. Make sure to get Sacrifice and Grave Robber. These combined with weapons that can give you health and mana bonuses will leave you nearly unstoppable in this area.
Blood Mage has one of the most powerful attacks in the game, known as Hemorrhage. If you can partner this with Paralyzing, you can attack enemies with a 900 percent increase while stunned.
source:
http://www.strengthgamer.com/Dragon_Age_2_Abilities.html