The three skill trees available for the Assassin class are Sniping, Cunning and Bloodshed. A good run through the game completing about 75% or more of the side missions will allow you earn enough skill points to work your way down to the bottom of one of these skill trees enabling the 'capstone' skill which will grant you special powers. The skill build I will be emphasizing in this walkthrough will be a 'power sniping' build of which I go into much greater detail here.
- Tier 1 skills
- Tier 2 skills
- Tier 3 skills
Note that unlike the original Borderlands, you do not have to put points on each and every tier of a skill tree to enable the next tier. For example, you could put 10 skill points in two Tier 1 skills (5 points each skill) to enable any Tier 3 skill. You can experiment creating your own Assassin class build by using the online Borderlands 2 Skill Tree. (NOTE: You may have to verify your age to access the online Skill Tree. Do so and then come back here and click on the link above again to gain access.)
Also keep in mind that the interactive Quick Change stations located in Sanctuary and Liar's Berg will —for a nominal fee— allow you to 'respec' your skill points. Essentially this means you can buy back all your skill points and reassign them as you wish. This is especially useful later in the game to create mission-specific builds.
Notes on Deception
Deception is the Assassin class action skill at the top of the Assassin Skill Tree screen. One skill point must be spent here before you can proceed to spend any further skill points in any particular skill tree. Once activated, you press the Action Skill key during combat to deploy a ghostly glowing blue holographic decoy which will last about 5 seconds. Enemies will either attack or react to the decoy as long as it is active.
The point of using the decoy is to give you time to carefully line up a headshot with a sniper rifle or sneak up close to an enemy and melee without fear of being attacked. The decoy can also be used to give you time to escape a dangerous situation or reload a weapon.
Any attack you make while the decoy is active —whether melee or gunshot— will have bonus damage. The only catch is as soon as you attack, the decoy is deactivated and you'll have to wait out a 15 second 'cooldown' period before deploying your decoy again.
Decoy bonus damage varies according to the type of attack and how long the decoy was active before making the attack. Attacks made just before the decoy's five second timer runs out get the highest damage bonuses. Regular non-critical hit attacks can get up to 200% bonus damage, critical hit attacks can get up to 250% bonus damage while melee attacks can get up to a whopping 650% bonus damage.