Death Sentry and Lightning Sentry are what most builds aim for, as they can deal out a massive amount of damage without you even getting close to the enemy. Traps are where the Assassin really excels, at least in PvE combat. Fade and Burst of Speed are both essential skills for most builds, and you can even sink points into Shadow Master if you'd like to summon a companion with access to all of your skills. Shadow Disciplines mainly provide buffs and boosts to the Assassin, to be used with either one of the other skill trees.
Because of the focused nature of these attacks, the Martial Arts tree is best suited for a life of PvP. With the right combination of passive and active abilities, a single strike from an Assassin can send a dueling opponent to an early grave. Martial Arts skills add normal and elemental damage to the Assassin's physical attacks. Many people, for player-versus-everyone (PvE) mode, will focus on Traps and Shadow Discipline, while players with PvP in mind will substitute Traps for Martial Arts. The skill tree is split into Martial Arts, Shadow Discipline, and Traps, generally offering up a mix of two trees for strong builds. The Assassin excels at PvP combat but can also be a potent late-game PvE class. Thanks to Diablo 2: Resurrected runewords, there's even a build that allows the Assassin to use the Barbarian's Whirlwind attack. Added in the Lord of Destruction expansion for original Diablo 2, she can either kick butt with spinning heels and fists or can lay deadly traps for unsuspecting victims. The Assassin is a truly interesting class that might not get enough love. Want to be sure each attack hits true, especially in PvP? Try Guided Arrow. Want to see hundreds of arrows pass through your enemies? Choose Strafe. Bow and Crossbow takes you down a different route, focusing on cold, fire, and magic damage.