Most of the music within Warcraft III was composed by Tracy W. Bush, Derek Duke, Jason Hayes, and Glenn Stafford. The Limited Edition of Reign of Chaos came with much of the orchestral music on a separate soundtrack. Each of the four playable races has different music: monastic music for the humans; ambient and Native American-sounding music for the Night Elves; warlike African-sounding music for the Orcs; and fast, haunting music for the Undead. New musical themes were added in the expansion.

One of the signatures of Blizzard games are the unit quotes. If a single unit is clicked four or more times in a row, the unit's voice samples become increasingly comical. The unit may start getting angry at the player, or make allusions and references to other games, movies, or jokes. Movies quoted include Monty Python, Blade Runner, Star Wars Episodes IV & V: A New Hope & The Empire Strikes Back, Army Of Darkness, and Toy Story. Games like Mortal Kombat, Warhammer 40,000, Blizzard's own StarCraft, and Banjo-Kazooie are paid homage, in addition to shows such as Saturday Night Live, The Twilight Zone, and Beavis and Butthead and Austin Powers: Goldmember.

As did Warcraft II and StarCraft before it, Warcraft III ships with a "World Editor" program that allows players to create their own custom scenarios and maps. The World Editor has features such as unit editing and event triggers. Through Battle.net, players can download and play peers' custom maps. To facilitate modding, third-party developers released tools for spell editing through SLK spreadsheets, customizing skins with .BLP converters, JASS editing, and a file importer that opened up .MPQs. The World Editor was expanded and improved for The Frozen Throne expansion. Though the editor has received updates through game patches, it is not officially supported as a product.

Some custom maps have enjoyed great success, with Defense of the Ancients (DotA) being a tournament item at Blizzcon 2005 and other tournaments around the world.[citation needed]. Various new types of games have been created included Role Playing and Tower Defense maps.

The game was announced with a press conference inside the Henley-Suite at the European Computer Trade Show 1999 around 1:00 PM. The development started in early 1998 and the development stages were presented at ECTS 1999, 2000 and 2001, E³ 2000, 2001 and 2002 and on a tour where Bill Roper visited computer game magazines.

The game was announced as role-playing-strategy game (RPS) with a flexible camera movement. The first version shown at ECTS 1999 had no interface, except portraits for the heroes. In articles from that time you can find that abilities and items were used via right-click on a unit and an appearing icon collar.

Around January 24, 2000 a video from Korea appeared on the Internet; it showed some gameplay and in the background Rob Pardo explained some things. This version already had an interface concept, but the most part of the interface were placeholders, it had map with some kind of 3D look, icons for abilities and orders and an eye-shaped display for gold.

Around April 19. 2000 Blizzard released some new screenshots of the game, these were completely without interface. These screenshots showed many heroes and some abilities and had a fixed but zoomable camera.

The next screenshots came around May 10. 2000. These screenshots showed the new interface of the game. It looks a little bit like the human interface of the release version, but has little cannons above the minimap and the command button space. The gold display is still eye-shaped, but the last screenshot before E³ 2000 shows a rectangle-shaped gold display. Most models, icons, textures and abilities that you can find on these screenshots never appeared in the retail version.