So you have set foot in the World of Sanctuary, spoken with Deckard Cain, and the Rogue Encampment is full of heroes bound for the realms. Before you march on Andariel, decide what your hero will become. Every class carries three skill trees, and the finest players pour their points into a single theme rather than dabbling everywhere. Synergies reward focus. Here are the builds that rule the realms.

Sorceress: the Blizzard Sorc. Feed the Cold tree: Blizzard for a killing storm of ice, Ice Blast and Glacial Spike as synergies, and max Cold Mastery to strip enemy resistance. Carry Frozen Orb plus a Fire or Lightning spell so the cold-immune packs in Hell do not stop you cold.

Paladin: the Hammerdin. Blessed Hammer from Combat Skills, driven by the Concentration aura from Offensive Auras, with Vigor for speed. Those spiraling hammers chew through Mephisto and duelists alike, which is why the Hammerdin is the most feared build on the Ladder.

Barbarian: the Whirlwind Barb. Take Whirlwind from Combat Skills and wade in dual-wielding. Back it with the Combat Masteries tree (a weapon Mastery plus Iron Skin) and a Battle Cry from Warcries to soften the Prime Evils before you spin.

Amazon: the Bowazon. Live in the Bow and Crossbow tree: Multiple Shot to clear packs, Strafe and Guided Arrow for single targets, with Penetrate and Critical Strike from Passive and Magic Skills. Her lightning-slinging cousin, the Javazon (Lightning Fury, Charged Strike), works the Javelin and Spear tree instead.

Necromancer: the Summoner. Max Raise Skeleton and Skeleton Mastery, add Skeletal Mages and Revives, and let your bone army do the dying. A Clay Golem, an Amplify Damage curse, and a hired mercenary round out a host that walks itself all the way to Baal.

A few rules hold for every build:

• Plan before you spend. Skill and stat points are permanent, so map your synergies first.
• Chase the gear. Rares, uniques, sets, and runewords define the endgame more than any single skill. Mind your sockets, gems, and charms.
• Answer the immunities. Every one-trick hero needs a second damage type for Hell difficulty.

Lord of Destruction owners get two more classes, the trap-laying Assassin and the shape-shifting Druid, each with three skill trees of their own. Whatever you choose, see you on the realms, and watch for hostile players in the duels.