Rogue Guide for Dragon Age 2: The Subterfuge Skill Tree
The Subterfuge skill tree gives the Rogue stealth capabilities and also enables them to jump out of harm's way. Skills from the tree can also be used to protect party members, give the Rogue a greater chance to cause critical hits when stealthed and also lower the threat they generate.
Stealth: Stealth allows the Rogue to fade from sight, even when in combat. It does reduce movement speed however and you cannot attack without revealing the Rogue's location. The upgrades reduce the movement penalty and also the cooldown, alongside making Stealth last longer. It's a pretty nice ability at the end of the day if your Rogur is nearly dead. Also, while you cannot attack without breaking stealth, you can at least ensure other abilities are guaranteed to critically hit when used from Stealth when the Ambush ability has been taken.
Evade: This skill enables the Rogue to leap backwards in an effort to avoid enemy attacks and it also reduces the Rogue's threat somewhat. The upgrade also allows the Rogue to stun enemies.
Chameleon's Breath: This skill allows the Rogue to obscure party members within a given radius, making it difficult for enemies to hit them. With the upgrade, the radius for the skill is increased, as well as the skill's duration.
Ambush: As mentioned above, this passive ability guarantees that abilities such as Hail of Arrows always critically hit when they're used from stealth. It's a nice ability to take.
Lingering Shroud: The Lingering Shroud ability enables the Rogue to use an ability without breaking stealth, as long as they're obscured. Once an ability is used, the obscure effect will be lost, so the Rogue is back to not being able to make any attack without breaking stealth.
Subtlety This passive ability is highly recommended because it reduces the threat that your Rogue causes by a flat 25%. So, you should really think about taking the ability.