Blood Omen: Legacy of Kain is an action-adventure game developed by Silicon Knights and published by Crystal Dynamics, with distribution involvement from Activision and BMG Interactive. It was released for the PlayStation in 1996, and a Microsoft Windows port was developed by Semi Logic Entertainments and released jointly by Crystal Dynamics and Activision in 1997. The game is the first title in the Legacy of Kain series.
Silicon Knights designed Blood Omen as "a game which adults would want to play", intending to evolve the action role-playing genre and bring artistic cinema to video game consoles. Reviewers praised its scope and storytelling, but criticized its lengthy loading times. After its release, a dispute arose concerning ownership of its intellectual property rights, after which Crystal Dynamics retained permission to continue the series with their 1999 sequel, Legacy of Kain: Soul Reaver.
Blood Omen introduces the land of Nosgoth, a fantasy setting dominated by humans and vampires. The health of the world is inextricably connected to the Pillars of Nosgoth — nine supernatural edifices, each one protected and represented by a human guardian. These sorcerers collectively comprise the Circle of Nine, and if a member dies, a new guardian is culled to take their place by the Pillars. Hundreds of years prior to the events of the story, the Circle formed and sponsored the Sarafan, an order of monastic warriors devoted to eradicating the vampire race, and in the game's prologue, the vampire Vorador reacts vengefully by killing six of the guardians and defeating Malek, the Sarafan leader. Though the Sarafan disband, vampires continue to be persecuted.
In the intervening years, new guardians have been summoned, Nosgoth's surviving vampires have retreated into hiding, and humanity has separated into two opposing factions: the kingdom of Willendorf, inspired by Arthurian legend, and the Legions of the Nemesis, an all-conquering army determined to bring an end to civilization. When the guardian of balance, Ariel, dies at the hands of a mysterious, malevolent entity, her lover Nupraptor the Mentalist turns his powers against his fellow Circle members, tainting the incumbent guardians with irrevocable madness and leaving the Pillars corrupt.
During a journey, the human nobleman Kain is ambushed and killed by a band of assassins. Mortanius offers him the chance to exact revenge — Kain assents, heedless of the cost, and awakes as a vampire. Once he kills his attackers, Mortanius tells him that, while they were the instruments of his death, they were not the ultimate cause. In search of the truth, and a cure to his vampiric curse, Kain travels to the Pillars of Nosgoth...
Kain (voiced by Simon Templeman), an ambitious, cynical young nobleman murdered and reluctantly raised as a vampire, is the protagonist of Blood Omen. Conceived as an antihero whose nature reflects the story's moral ambiguity, Kain was partially modeled on the character of William Munny from the 1992 Clint Eastwood film, Unforgiven. Mortanius the Necromancer (Tony Jay), an ancient wizard, resurrects Kain in a Faustian bargain, and serves as his enigmatic benefactor and semi-father figure throughout the game. The reclusive and decadent vampire Vorador (Paul Lukather) acts as a mentor and father figure to Kain, encouraging him to accept vampirism, whereas the specter of the deceased balance guardian, Ariel (Anna Gunn), directs Kain in his quest to restore the land. The corrupt guardians — such as Moebius the Time Streamer (Richard Doyle), a devious manipulator of history, and Malek the Paladin (Neil Ross), now an animated suit of armor eternally condemned to protect the Circle following his defeat against Vorador — feature as the villains in the game. Other major characters include King Ottmar (Ross), the ruler of Willendorf; The Nemesis (Jay), a once-benign monarch known as William the Just, turned despot and tyrant; and The Dark Entity (Jay), an otherworldly being capable of demonic possession who is the overall mastermind and a primary antagonist and final boss of Blood Omen who seeks to topple the Circle and the Pillars and establish the reign in Nosgoth.
Blood Omen is a two-dimensional action-adventure game. The player controls the protagonist, Kain, from a top-down perspective. Gameplay is divided between outdoor traversal and dungeon crawls, entailing hack and slash combat, puzzle-solving, and navigating hazards. To advance the story, Kain must locate and defeat the members of the Circle of Nine — who act as boss enemies — and return their tokens to the Pillars of Nosgoth. Humans, animals, and a variety of fantasy creatures inhabit the game world, whom the player can typically elect to kill outright, or alternatively wound in order to feed on their blood. As a vampire, Kain is required to consume the red blood of living creatures to replenish his health meter, which gradually drains over time, and diminishes more quickly if he sustains damage. When he casts spells or shapeshifts, he expends magic energy — this recovers in time, and can be replenished by drinking the blue blood of ghostly enemies. Conversely, undead opponents relinquish harmful black blood, and demons and mutants yield green blood which poisons Kain, causing his health to deplete at a swifter rate.
Over the course of the main quest, Kain acquires many items and abilities, which facilitate increasingly nonlinear exploration. As he collects blood vials and rune pyramids, Kain's maximum blood and energy capacity rises. By drinking from blood fountains, he receives strength upgrades, faster magic regeneration, and immunity to weather effects. Weapons include iron and fire-elemental swords, a spiked mace, twin axes, and the Soul Reaver, a two-handed flamberge. Suits of iron, bone, chaos, flesh, and wraith armor feature, and each combination of equipment has advantages and drawbacks. Spells, in the form of magical tarot cards, are used in both strategic and practical contexts, their functions ranging from summoning artificial light to mind control and the evocation of lightning storms. Shapeshifting enables Kain to assume the forms of a bat, allowing for immediate travel to checkpoints; a wolf, with enhanced speed and the capacity to jump; a cloud of mist, which enables him to pass through gates and cross water; or a human, with which he can covertly interact with, or bypass, certain non-player characters.
There are 100 secrets present in the game, logged if the player uncovers hidden areas, switches, and dungeons; these encompass spirit forges, at which Kain may donate a significant portion of his blood in exchange for powerful battle artifacts. A day and night cycle passes progressively — at night, Kain's attacks become more potent, and during full moon phases, some sealed doors become accessible.