LSD: Dream Emulator is an exploration game developed and published by Asmik Ace Entertainment for the PlayStation. In LSD, the player explores surreal environments without any objective. The player can only move and touch objects that will warp them to another setting. The game was conceived by Japanese artist Osamu Sato, who rejected the idea of games, and wanted to use the PlayStation as a medium for creating contemporary art. The game's settings are based on a dream diary kept by Asmik Ace employee Hiroko Nishikawa for over a decade. The game was released only in Japan on October 22, 1998.

The game received a limited release exclusively in Japan alongside a soundtrack and a book composed of excerpts from the dream diary. LSD quickly fell into obscurity, but in years since has experienced a resurgence in popularity on the internet due to its eccentricity being an engaging point of discussion for humor blogs and Let's Play commentators. In retrospect, critics have praised its whimsical qualities called it one of the most "unnerving", "experimental", and "unpredictable" video games of all time. By popular demand, LSD was re-released on the PlayStation Network in 2010 in Japan.