Unlike Dota 2, which uses a server-side authoritative model, Dota 1 was a custom map built on Blizzard’s Warcraft III engine. This engine used a networking architecture.
Instant alerts when Roshan was being attacked or when a new rune spawned. The Impact on the Game dota 1 maphack work
Maphack developers used various software tools to alter how Warcraft III processed its local memory. The most common methods included: 1. Memory Address Alteration (RAM Patching) Unlike Dota 2, which uses a server-side authoritative
Since the game engine itself didn't "know" who was looking through fog, the community developed creative detection methods: Unlike Dota 2