Something remarkable is happening in the custom game lists on the Internet Gaming Zone. Warcraft III: Reign of Chaos arrived with a World Editor so deep that players are no longer content to fight over Lost Temple, Turtle Rock, and Echo Isles. They are building entirely new games on top of Blizzard's engine, and the results are drawing crowds every single night.

The secret is the trigger system. Using the point-and-click editor, or the underlying JASS scripting language for the ambitious, mapmakers can bend the rules of gold, lumber, and food upkeep to their will. Heroes that level up, carry items, and cast abilities were built for the four-race ladder, yet they turn out to be perfect raw material for wholly new modes.

Three genres now rule the lobby:

• Tower Defense. Waves of creeps march along a fixed path, and your job is to line it with towers before they slip past. Cooperative "mazing" variants let a whole team pool gold to hold the line together.
• Defense of the Ancients. Two teams, the Sentinel and the Scourge, each pick a single hero and push three lanes. Slay enemy units for gold, buy items, and tear down the rival Ancient. DotA Allstars has become the room to beat.
• Hero Arenas. Strip away the base building entirely. Players spawn a lone hero, farm neutral creep camps for experience and loot, then hunt one another across the map until one side runs out of lives.

What makes it all click is that the pieces were already there. Blademasters, Death Knights, Priestesses of the Moon, and Archmages behave exactly as they do on the ladder, so the learning curve stays gentle even when the mode is brand new. Neutral creep camps hand out the same experience, gold, and items whether you are seated on a ranked map or a homemade arena.

With The Frozen Throne now expanding the editor's toolbox, expect the flood to continue.
Host a custom game on the Zone tonight, and you may find that the most popular room in the house was written by a player just like you.