Sales

Conflicting figures exist on the sales of Doom and Doom II, but it is certain that both games are million-sellers.

Two different sources give the following numbers:
 * 1) The year 2000 edition of The Complete Wargames Handbook provides figures for the best selling computer games between 1993 and 1999. It puts Doom II as number three, with 1.5 million copies (behind Myst with 4.2 and Microsoft Flight Simulator with 2.8). Doom ends up number 8, with 1.1 million, and Ultimate Doom number 20, at 788,000.
 * 2) A list by now-defunct research firm PC Data for January 1993–April 1998 puts the sales for Doom II at 1,815,882 and Doom at 1,361,943, on positions 3 and 4.

Based on these data, one may place the sales until 1999 in the range 1.9–2.1+ million for Doom (including Ultimate Doom), and 1.5–1.8+ million for Doom II. It is probably safe to deduce that as of 2005, both Doom and Doom II have sold well over 2 million copies each. (The Page of Doom verifies, though no source is cited for the claim, that Doom II had "an initial release of over 0.5 million, and 2 millions sold to this day" .) Hence, the PC versions of Doom and Doom II have likely sold over 4 million copies combined. This number does not include sales for the console versions of Doom, nor Final Doom, which when added may put the total for the entire original Doom franchise significantly higher.

Although Myst and Microsoft Flight Simulator have sold more, it must be noted that Doom has been distributed primarily in its free shareware version. The most common estimate is that it has been played by 15 million people.

In a press release by Mindscape Entertainment dated July 19, 1999, another report from PC Data is cited according to which "Doom" sold 2.9 million copies between 1994 and 1999. It is not clear whether this refers to Doom and Doom II, Doom and Ultimate Doom, or some other combination. If it refers to Doom and Doom II, it is inconsistent with the aforementioned figure from PC Data which puts the combined sales for shareware Doom and Doom II at 3.2 million (the difference of one year hardly provides sufficient explanation; it would imply that in the first 20 days after its release, shareware Doom sold 300,000 more copies than Doom and Doom II did combined in 1999). It does however make some sense if taken to mean Ultimate Doom and Doom II combined. In any case, it can probably be ignored in favor of the more specific numbers from the 1993–1998 report and the Handbook.

According to PC Magazine, June 27, 1995, Doom II was the second best selling CD-ROM game of 1994