A 60 year old videogame just hit its highest player count ever on Steam and I'm pretty sure it's because people are pirating Schedule 1

At time of writing, SteamDB's concurrent player ranking is led by the usual suspects: Counter-Strike 2 is commanding its expected lead with more than a million players while Dota 2 and the breakout drug-selling sim Schedule 1 follow behind. A bit farther down the list, however, is an unexpected title that hit its all-time peak player count just two days ago: It's called Spacewar, and in all likelihood, very few of its current 100,000 players are actually playing it.

How? Well, piracy, probably.

The original Spacewar was one of the world's first videogames, released all the way back in 1962. It's a bit like Asteroids, except instead of blowing up space rocks, players attempt to destroy each other while maneuvering around a gravity well in the center of the screen.

Even if you aren't aware of it, you already own the Steam version. Just enter "steam://run/480" in the address bar of your browser on a machine with Steam installed, and you'll be able to play it after a meager 1.8 MB download.

Spacewar is freely available because its source code is included in the Steamworks SDK as an example project, demonstrating for game developers how to implement Steam's various networking, distribution, and community features. Because Spacewar's got all of Steam's bits and bobs like avatars, friendslists, and matchmaking built in, devs can check against its code when putting those same Steam features in their own games.

Valve also allows developers to use Spacewar's AppID—an identifying, software-specific number assigned to each game listed on Steam—to test networking features during game development. For example, Unreal Engine uses Spacewar's AppID, 480, as a default so that Unreal developers can test Steamworks feature integration.

What a freely-usable AppID also allows, however, is a convenient avenue for players with pirated copies of Steam games to access Valve's multiplayer services.

Because you'd likely trip some alarms if Steam noticed you were trying to play multiplayer with a game your account doesn't own, it's common for cracked versions of pirated Steam games to spoof Spacewar's AppID. You might be playing multiplayer in illicit software, but to Steam—and SteamDB, and all your Steam friends—it'll look like you're playing Spacewar.

So why the recent spike in Spacewar numbers? If you look at its player activity chart on SteamDB, you might notice that its player count started increasing steadily on March 24—the same day that Schedule 1 launched.

Looking further back, you can find similar spikes around the launch of breakout Steam successes and meme games, like Palworld in January 2024 and the early access launch of Sons of the Forest in February 2023.

As for why the latest spike was the largest: I think we can safely suspect there's a Venn diagram overlap between digital piracy and simulated crime.