Two college students, Rick Taylor and Jennifer Willis, take refuge from a storm in West Mansion, a local landmark known as "Splatterhouse" for the rumors of hideous experiments purportedly conducted there by Dr. West, a renowned and missing parapsychologist. At the mansion, the two are attacked by demonic creatures that drag Jennifer inside and fatally wound Rick, leaving him for dead.

Rick awakens in the dungeon of the mansion to discover that he is still alive thanks to the influence of the "Terror Mask", or in some versions, the "Hell Mask", a Mayan sacrificial artifact from West's house which is capable of sentient thought. The mask attaches itself to Rick, fusing with his body and transforming him into a monster with superhuman strength. With the mask's encouragement, Rick goes on a rampage through the dungeon and the mansion grounds, killing hordes of monsters. Inside the mansion, Rick finds Jennifer, prone on a couch and surrounded by a throng of creatures that retreat upon his arrival. After their departure, Jennifer transforms into a giant, fanged monster that attempts to kill Rick while begging him for help. Rick is forced to kill Jennifer, who transforms back to normal and thanks him before she dies. Infuriated, Rick tracks the remaining monsters to a giant, bloody hole in the mansion's floor. Upon entering it, Rick discovers that the mansion itself is alive. He follows a bloody hallway to the house's "womb", which produces fetus-like monsters that attack him. Rick destroys the womb, which causes the house to burst into flames as it "dies".

Escaping the burning mansion, Rick comes across a grave marker. The Terror Mask releases energy into the grave, reviving a giant monster named Hell Chaos that claws its way up from the earth and attempts to kill Rick. Rick destroys the creature, which unleashes a tormented ghost that dissipates into a series of bright lights. As the lights vanish, the mask shatters, turning Rick back to normal, and he flees as the house burns to the ground and the credits roll. However, after he leaves and the credits end, the Terror Mask reassembles itself and laughs evilly, staying there for 45 seconds, with the word "END" appearing on the bottom right corner of the screen.

Splatterhouse was released in various home version ports on the TurboGrafx-16, FM Towns and PC. Though the Japanese PC-Engine (the Japanese name of the TurboGrafx-16) version of the game remains largely unedited, the Western TurboGrafx-16 version features a number of changes, as well as standard changes for an arcade port at the time, caused by the less-powerful hardware of the console (loss of graphical detail, removal of some sounds). They include the following:

• The arcade version opens with an animation of Rick and Jennifer running through the storm and into the mansion, followed by an exterior shot of the mansion and the sound of Jennifer screaming. The console version opens simply with the exterior of the mansion, and no sound effects.
• The Terror Mask is changed from a white hockey mask to a red mask with black accents in the US Turbografx version. This is to keep Rick from looking too much like Jason Voorhees. The mask became more skull-like in later games.
• The first weapon in Stage 1 is changed from a meat cleaver to a 2x4.
• The overall violence and gore is toned down; enemies bleed less and the sound effects are less gruesome.
• In the arcade version, the Stage 4 boss fight takes place in a chapel. After defeating the boss, Rick approaches an altar with a crucifix and sunlight shines in through the windows as a hymn begins to play. Several seconds later, suspenseful music plays followed by Jennifer screaming. In the US Turbografx version, the chapel is a generic hallway. After defeating the boss, Rick inexplicably approaches a large, empty room; the hymnal, sun animation, and suspenseful note are left intact but Jenifer's scream is removed for an unknown reason.
• The Stage 4 boss in the arcade version is "Evil Cross," a giant, inverted cross surrounded by floating severed heads. In the console version, the cross is replaced with a new enemy, a demon's skull called "Evil Sleep." The heads are referred to as "Nightmares," and only three of the six present in the arcade version appear. Also, the weapon for the boss is changed from an axe to a gold meat cleaver, the only cleaver in the game.
• The death of the womb boss of Stage 6 is changed from a graphic spilling of embryonic fluids into a generic fiery explosion in the console versions (both western and Japanese releases).
• The final boss uses different attacks in the console version.
• The final boss' grave is changed from a wooden cross to a tombstone in the western console version.
• The end cut scene is changed from the original arcade ending, in which the mask breaks from Rick's face, followed by a shot of him walking away from the burning mansion and an additional cut scene showing the mask reform and laugh. The ending in the TurboGrafx-16 version only shows the mask explode, followed by a picture of West Mansion burning while the credits roll, and finally a large red and orange "End" is displayed.

The TG-16 version was also released on the Wii's Virtual Console in Europe on March 16, 2007 and in North America three days later on March 19, 2007. The version of the game ported to the Wii Virtual Console is the western TurboGrafx-16 port; therefore it is the "censored" version as opposed to the "uncensored" original arcade game. Namco Bandai had announced that the arcade version would be ported to the Japanese Virtual Console and was released on May 26, 2009. There are currently no plans for a U.S. release.

The FM Towns version, ported by Ving Co. and released only in Japan in 1992, is a pixel-perfect rendition of the original arcade, with no substantial changes apart from a new menu interface in the title screen. There was also an LCD handheld version released, Splatter House, but it is not a port of either games. It is considered to be an original Splatterhouse game in and of itself, though many elements in it are similar to the original game.

There is also a version available for mobile phones. The only change in this version is that Rick's mask will look like how it does in the 2010 remake.

It was then ported to iPhone, iPod Touch, iPad. The mask in that version looks like how it does in the original arcade game, but it now adds a "Splatter Rush" mode where enemies continuously spawn from both ends of a wide screen with music from the 2010 remake playing in the background.

The original arcade game was included as an unlockable extra in the 2010 remake.[1]

Splatterhouse generated an outcry and calls for it to be banned in its original arcade form, due to extreme graphic violence. This is notable because in the days before video game manufacturers had ratings standards, it was rare for any game to be banned. A more muted response occurred over the ported PC-Engine/TG-16 release.

IGN's Lucas M. Thomas said of Splatterhouse that "Putting aside the aesthetic design and just looking at the game on the merits of its mechanics, Splatterhouse is lacking." He complained about the limited variety of attacks, one way scrolling, and censorship present in the North American console version. Thomas did, however, compliment the game's horror themes and music, noting that the console graphics, despite being "toned down", are a "good representation of the arcade original." Frank Provo of GameSpot had similar complaints about Splatterhouse. "Ultimately, the problem with Splatterhouse is that there's not much to it. There are only seven levels, and you'll finish each one in just a few minutes", he wrote, going on to explain that the enemies all follow easily memorized patterns, making the game very simple to play. In particular, Provo criticized the fact that the Virtual Console version was the censored console version, noting how he missed the meat cleavers and extra violence of the arcade game. A review at Pauseitmedia.com praised the game, saying that "Namco’s arcade beat ‘em up Splatterhouse was one of the earliest games to receive the attention of concerned parents, and its twisted imagery would go on to pave the way for other horror-themed games."