Steam

Steam is where co-op gaming is cheapest

If your group is on PC, Steam is the platform that makes multiplayer affordable. Its sale cycle is aggressive enough that most of the picks below have sold for a fraction of their list price at some point in the last year, and the library includes a whole category of small, cheap, four-player co-op games that never reach consoles at all.

Helldivers 2 tops the list because it is the rare title that is both a genuine headline release and a four-player co-op game first - and its crossplay reaches PS5, so a PC group with one PlayStation friend is still fine. Deep Rock Galactic is the better value pick: four-player procedural co-op with enormous replayability that is almost always cheap.

Then Steam's specialties. Portal 2 has the best two-player puzzle campaign ever made and costs almost nothing. Lethal Company and Phasmophobia are the co-op horror games that defined the genre on PC - neither is sold on Amazon, so check their store pages directly. Terraria and Human: Fall Flat round out the cheap end, and Apex Legends, Fall Guys, and Rocket League cost nothing at all.

Remote Play Together: local co-op over the internet

This is Steam's best and least-known feature for groups. Remote Play Together lets you stream a local multiplayer game to friends over the internet, and only the host needs to own it. That turns every couch co-op game in your library into an online one for free. It works well for slower games - platformers, puzzle games, party games - and less well for anything twitchy, since input travels over the network. If you own a local-only co-op game and your friends do not, try this before buying more copies. It also solves a hardware problem, not just a cost one: because the host runs the game and the guests receive a stream, a friend on a low-end PC or old laptop can play something their machine could never run locally.

Check the co-op tags before you buy

Steam distinguishes between "Online Co-op", "Shared/Split Screen Co-op", and "LAN Co-op" on every store page, and they are not interchangeable. A game tagged only for shared screen will not let you play online with a friend in another city without Remote Play Together. Read that box; it prevents most disappointing purchases.

The Steam picks by group size

Two of you. Portal 2, first and cheapest. Its co-op campaign is a separate mode built for exactly two, and it goes on sale for a couple of dollars regularly. See our 2-player page for the wider list.

Three or four.Deep Rock Galactic, Helldivers 2, Lethal Company, or Phasmophobia. This is Steam's strongest bracket by a distance - four-player co-op is the format PC does better than anywhere else.

Five or more. Terraria handles up to eight and Human: Fall Flat also goes to eight, both cheaply. Beyond that you are into free battle royale territory - Apex Legends and Fall Guys. Our large groups page has more.

Steam and crossplay

Being on Steam does not stop you playing with console friends, but it depends entirely on the game. Helldivers 2 reaches PS5 and Xbox. Deep Rock Galactic reaches Xbox but not PlayStation. Human: Fall Flat, Overcooked, Fortnite, Rocket League, and Fall Guys reach everything. Portal 2, Lethal Company, Borderlands 3, and Phasmophobia are effectively PC-bound for your purposes. The crossplay hub has the verified list, and PS5 + PC and PC + Xbox cover the two most common mixes.

Refunds make trying a co-op game low-risk

Steam's refund policy - broadly, within a couple of weeks of purchase and under roughly two hours of playtime - is unusually useful for group games. It means a squad can each buy a co-op title, play one session together to find out whether it clicks, and everyone can return it if it does not. Very few purchases in gaming come with that safety net, and it takes most of the risk out of trying something nobody in the group has played.

Two practical notes: the playtime limit is per person, so tell everyone before you start rather than after, and a heavily discounted purchase refunds the amount you actually paid. Check the current policy at the point of buying, since terms can change.

Wishlist rather than buy

Steam runs major seasonal sales several times a year, and wishlisted games email you when they discount. For a group planning a co-op purchase that is not urgent, wishlisting the two or three candidates and waiting for a sale is the single easiest way to halve the cost. Prices shown on this page come live from Amazon, which is a separate market from Steam's own store - compare both before buying, and see our budget picks for the consistently cheap options.