Immortal is a roleplaying game of immortals. Not Gods in the sense of Dungeons and Dragon's Gold Covered Immortal Rules (which deserves its own writeup), but creatures with powers on the scale of the angels and demons of In Nomine. Its first edition was called Immortal: The Invisible War and it was set during the period it was released, during the summer of 1994. The second edition is called Immortal: Millenium and is set somewhat in the future, but still within the 21st Century. It was originally owned by Precedence Publishing.
As was popular with all the roleplaying systems of the time, they took a cue from Vampire: the Masquerade and released clan-based (they called them prides) character generation. In fact, it borrowed heavily from that RPG, with quotes for chapters, careful attention to artwork, and a very goth-punk feel, even a pride which was very similar to vampires, the Anopheles. However, it used full color artwork (very computer generated) and a "Perception defines reality" style of magic, before Mage: the Ascention.
In this game, you play a creature that was part of the legends of the past. You awaken in the modern times, with few memories of the times past. The entity which created you is now enslaving humanity, and trying to destroy the world, but completely beyond the knowledge of the mundane world.
The prides of Immortal are: Anopheles, Arachne, Banjax, Dracul, Eremites, Magdalen, Morrigan, Nimrod, Peri, Phoenix, Roane, Tautha, and Terat. Some of these should seem very familiar, they were based on various legends and stories.
The new version of the game only requires that you buy the base book. All other info on the game is available as a free download, as Adobe Acrobat files. Also, the world is a shared one. If you want to upload info on the exploits of your characters to the website, they will merge it into the official storyline. (Apparently, Claudia Christian in the role of the character Shade resulted in serious changes in the campaign world.)
I attempted to play the game, but unfortunately never managed to convince a group to play it. I did learn that the character sheet was next to impossible to photocopy. (It was in color and I ended up needing to buy character sheets for it. They were also in color.) The system played "silly dice tricks" once again, and from what I've heard, the newer version plays even sillier dice tricks. There is work being done on a new third edition, which attempts to bring the first and second editions back together.