Diablo II: Lord of Destruction/Shadow Disciplines

It is the shadow disciplines that really give the assassin her own unique character. We associate assassins with stealth, speed, and poison, and it is these disciplines that make her excel at these skills. An assassin who emphasizes the shadow disciplines will not need to put as many stat points into strength and dexterity as a martial artist would, because she may rely on her shadow master and converted mind blast foes to do her dirty work.

Claw Mastery
Katars, hatchet hands, and other claw-class weapons are an assassin's best weapons, making this skill very useful. At least one skill point should go into claw mastery to get an easy one-third boost in both damage and attack ratings.
 * Description: Improves claw-class fighting skill
 * Level prerequisite: 1
 * Skill prerequisite: None
 * Mouse button: Passive

Psychic Hammer
A ranged attack, psychic hammer can strike any visible enemy, not just those near your character. It is best learned so you can then advance to the more powerful skills, like cloak of shadows and shadow warrior.
 * Description: Knocks enemies back while damaging them
 * Level prerequisite: 1
 * Skill prerequisite: None
 * Mouse button: Right

Burst of Speed
An extremely useful early skill, burst of speed lets you not only attack more quickly but also get from point A to point B with greater haste than any other character class. Note that when burst of speed has been cast, it cancels the effects of both fade and venom.
 * Description: Increases both moving and attacking speed
 * Level prerequisite: 6
 * Skill prerequisite: Claw Mastery
 * Mouse button: Right

Weapon Block
This skill does not provide any bonus to a moving assassin, and its blocking statistics do not easily approach those provided by certain fairly common shields. Further, blocking does damage to claw weapons, which drives up repair costs. It is, however, a requirement for shadow warrior, which is a very useful skill.
 * Description: Allows an assassin with dual claw-class weapons to block
 * Level prerequisite: 12
 * Skill prerequisite: Claw Mastery
 * Mouse button: Passive

Cloak of Shadows
This spell affects enemies within a certain radius of the player (or shadow fighter) who casts it. Any enemy who has not already spotted you (or a member of your party) will act as if you are not present, although if you bump into such an enemy, your presence will be revealed to it. Any enemies that already knew of your presence will come to the spot where they last saw you, making it wise for you to move to one side after you cast this spell. You cannot stack this spell but must wait for the duration before you can recast it.
 * Description: Conceals the assassin for a short time
 * Level prerequisite: 12
 * Skill prerequisite: Psychic Hammer
 * Mouse button: Right

Fade
Some enemies possess special attacks (fire, poison, and so on), and this spell is best saved for the times when you face such foes. Note that when fade has been cast, it cancels the effects of both burst of speed and venom.
 * Description: Increases all resistances and protects against curses
 * Level prerequisite: 18
 * Skill prerequisite: Burst of Speed
 * Mouse button: Right

Shadow Warrior
A shadow warrior lives until her life runs out. The best time to summon a shadow warrior is in town, where you can instantly replenish your mana at no expense. A shadow warrior uses only the two skills that you have equipped, but it is not necessary to summon a new shadow warrior when you wish to switch to new skills, as she will follow your lead and begin using the new abilities. You cannot equip a shadow warrior, and you may only summon one at a time. You cannot directly heal her, although her life will return to full if you contact the appropriate shopkeeper in town who returns the assassin's life to full.
 * Description: Summons a mimic assassin who uses your two equipped skills
 * Level prerequisite: 18
 * Skill prerequisite: Weapon Block, Cloak of Shadows
 * Mouse button: Right

Mind Blast
Mind blast affects enemies in a small area in the direction it is aimed. It is not necessary to attack an enemy with mind blast; simply clicking the ground is sufficient. Mind blast can attack any enemy or point that is visible to your character, not just those near you. Because of its chance to convert, this spell is best used against a crowd of enemies; it is possible to convert multiple enemies with one casting. Aim in such a way that the maximum number of enemies are affected by this spell.
 * Description: Stuns and damages nearby enemies, with some chance of temporary conversion
 * Level prerequisite: 24
 * Skill prerequisite: Cloak of Shadows
 * Mouse button: Right

Venom
Although the duration of this spell is quite long, it is best to cast it just before you intend to use it. Remember that poison damage extends over a period of seconds; it is therefore best to use it once on a monster and then switch to new targets so that the enhanced poison damage will have its full effect on each target. Note that when venom has been cast, it does not cancels the effect of fade.
 * Description: Temporarily adds poison damage to an equipped weapon
 * Level prerequisite: 30
 * Skill prerequisite: Fade
 * Mouse button: Right

Shadow Master
A shadow master behaves more or less like a shadow warrior, with the exception that she can use any assassin skill. The best time to summon a shadow master is in town, where you can instantly replenish your mana. Only one shadow master may be present at a time; summoning either kind of shadow fighter will banish any existing one. You cannot equip a shadow master, and you cannot directly heal her, although her life will return to full if you contact the appropriate shopkeeper in town who returns the assassin's life to full.
 * Description: Summons a mimic assassin who uses all of your learned skills
 * Level prerequisite: 30
 * Skill prerequisite: Shadow Warrior
 * Mouse button: Right