The light whooshing sound heard when a stealthed enemy gets close to a player in World of Warcraft is a useful cue that seems like something deliberately designed by Blizzard, but according to a video from Eurogamer the audio trigger wasn’t intentionally part of the game's stealth system.
Instead, the sound first happened as a side-effect of how World of Warcraft servers communicate information about cloaked characters to individual game clients, according to information gathered from Blizzard's Geoff Goodman.
A full explanation can be found in the short video above, but this situation is especially interesting because it also offers a closer look at the unique technical challenges posed by player vs player combat in online games like World of Warcraft.
The sound ended up becoming a useful indicator of approaching danger and, following a few tweaks, eventually became a permanent feature in the game.
The video itself is part of a new series from Eurogamer called Here’s a Thing that highlights interesting stories about games and game developers through weekly videos.
This first episode is short and sweet, but game developers might do well to keep an eye on the series later on. Future videos covering things like Nintendo’s relationship with emulation and Sid Meier’s rulebook for designing the Civilization games are already in the works.