Definition of "Doomer"

Doomers, ranging from children to senior citizens, are up all night hunting specters, imps, and other hellspawn, battling each other in so-called Deathmatch tournaments, and checking out the latest Doom lore by conversing with the game’s developers over computer chat lines. […] What’s ahead for Doomers? Id has authorized a company called Austin Virtual Gaming to license an eight-screen Doom arcade setup around the country.

1994, BusinessWeek, page 16

I am not a female Doomer, but I did "catch" my fiance playing Doom the other day. It led us to a discussion of why ID didn't put the option in to choose a female character.

1994 April 30, Ricardo Lopez, “Are there any *female* doomers out there?”, in alt.games.doom‎ (Usenet)

The sense of reality is so seamless that on the Internet, where many Doomers gather, there is a FAQ (frequently asked questions) document that talks about Doom-induced motion sickness. […] At one point, Carnegie Mellon University’s 25,000-user network had so many student Doomers playing that the system nearly ground to a halt.

1994 September 23, Robert S. Cauthorn, “‘Doom’s Day’: Oct. 10 is release date for sequel to wildly popular game”, in The Arizona Daily Star, volume 153, number 264, Tucson, Ariz., section E, page twelve

#doom This channel is a cousin of #vidgames […] And some players use it to find others who have the Internet Head-to-Head Daemon (IHHD) software, which lets folks play Doom over the Net. (Note: Some “Doomers” may want to try finding the #modemdoom channel if #doom is not active for some reason.)

1995, Donald Rose, Internet Chat Quick Tour: Real-time Conversations & Communications Online, Ventana Press, page 119

On the downside, they’ve created such indelible demons and Death match tournaments that Doomers of all ages have reported actual perception changes.

1996, Faith Popcorn, Lys Marigold, Clicking: 16 Trends to Future Fit Your Life, Your Work, and Your Business, HarperCollins, page 86

By intentionally leaving cracks in his source code, [John] Carmack encouraged Doomers to hack the game and create their own elaborate levels — new battlegrounds upon which the carnage took place.

1999, The New York Times Biographical Service, page 786

“Doom is a great stress-reliever,” said Lewis. “Its[sic] a great way to blow off stress after a bad day.” This defense is rather common among “Doomers,” as Doom enthusiasts have come to call themselves.

a. 2003, Mathew Webb, “Is it doom for Doom?”, in Cougar Chronicle, Austin, Tex.: Hill Country Middle School; quoted in Homer L. Hall, “Those Opinionated Columns”, in Junior High Journalism, New York, N.Y.: The Rosen Publishing Group, Inc., 2003, page 189