Key Takeaways
- Steam’s Free Weekend runs from now until September 21, 2026 at 10am PT / 1pm ET — after which the games revert to paid.
- Four games are available this weekend: Diablo 4, Sea of Thieves, Last Flag, and Jump Space.
- This weekend’s selection skews hard toward co-op and multiplayer, making it perfect for gaming with friends.
- Diablo 4 is 75% off ($49.99 → $12.49) until September 24 for anyone who wants to keep playing after the free weekend.
- Sea of Thieves is 65% off ($39.99 → $13.99) until September 27.
- Jump Space is 40% off ($19.99 → $11.99) until September 24.
- Last Flag remains at its regular price of just $4.99 — no discount needed.
- Steam Free Weekend games are temporary access, not permanent — unlike Steam’s separate Free-to-Keep promotions.
Got a weekend free and want to fill it with something you haven’t tried yet? Steam’s Free Weekend promotion has you covered through September 21. Four games are on the table right now — and this particular weekend’s lineup is almost entirely built around co-op and multiplayer experiences, so grab a few friends and clear your schedule. Here’s the full breakdown.
What Is Steam’s Free Weekend Promotion?
Quick clarification before jumping in, because Steam runs two different types of free game offers and people mix them up constantly. Steam’s Free Weekend Promotions give you full access to a game for a limited period — in this case, through September 21 at 10am PT / 1pm ET — but that access disappears when the timer hits zero. You can play as much as you want during the window, but you don’t keep it. If you enjoy what you played, the good news is there’s almost always a discount lined up so you can grab it at a reduced price before it expires.
The other type — Steam’s Free-to-Keep promotions — are the opposite: you claim the game by a specific date and own it permanently, even if you never install it. Completely different system. This weekend’s games fall under the temporary Free Weekend category, so play them now rather than banking on keeping them.
Diablo 4
If you haven’t touched Diablo 4 yet, this weekend removes every excuse. Blizzard’s action RPG is set in the dark, sprawling world of Sanctuary, where you build a character from one of the available classes, push through a lengthy campaign, clear dungeons, take down increasingly difficult bosses, and assemble a gear build that gradually turns you into something terrifying. The campaign can be played solo or in co-op, which fits perfectly with this weekend’s theme.
The endgame is deep enough that even a full weekend of playing won’t scratch the surface — seasonal content, world bosses, and the kind of gear optimization rabbit hole that has kept players busy for years. Diablo 4 has also come a long way since launch through multiple seasons of updates that significantly reworked core systems and added content. If you tried it at launch and bounced off, this is a fair shot at a much better version of the game.
- Genre: Open-World Action RPG
- Developer/Publisher: Blizzard Entertainment
- Steam Review Rating: 73% Mostly Positive (21K+ reviews)
- Can you finish it this weekend? No — it’s massive.
- Purchase Discount: 75% off until September 24 ($49.99 → $12.49)
Sea of Thieves
Sea of Thieves has one of the best free weekend pitches in gaming: you and your crew are pirates. You sail a ship across a shared open world, dig up buried treasure, complete voyages, fight other crews, hunt the Kraken, discover secret islands, and try not to lose everything when your ship takes on water five minutes from the outpost. The entire game revolves around that tension of getting loot safely back to port — and it creates genuinely memorable moments even when (especially when) everything goes catastrophically wrong.
Rare has added an enormous amount of content since the game launched on Steam in 2020, including a full narrative campaign, seasonal events, fishing, ship customization, and PvE modes for crews who want to avoid player conflict. The 88% Very Positive rating across nearly 150K reviews on Steam reflects just how well it’s held up. This one is genuinely best with friends, and with four-player crews being the sweet spot, a group free weekend is exactly what Sea of Thieves was built for.
- Genre: Action Adventure Sandbox
- Developer: Rare
- Publisher: Xbox Game Studios
- Steam Review Rating: 88% Very Positive (147K+ reviews)
- Can you finish it this weekend? No — there’s no finish line.
- Purchase Discount: 65% off until September 27 ($39.99 → $13.99)
Last Flag
This one has a fun origin story. Last Flag was built by Night Street Games, an indie studio co-founded by Mac and Dan Reynolds — the latter being the lead singer of Imagine Dragons. The soundtrack was composed by Dan Reynolds himself alongside Grammy-nominated producer JT Daly and Dave Lowmiller, who has credits on Call of Duty: Modern Warfare and Battlefield. The music is built around real vintage instruments for an authentic 1970s feel — because Last Flag is set in a funk-inspired alternate-universe TV game show where capture the flag is the world’s most-watched sport. Yes, really.
The gameplay is a 5v5 third-person hero shooter built entirely around the CTF format, but elevated. Teams get 60 seconds at the start of each match to hide their flag somewhere on the map. Then the hunt begins. Each character brings unique abilities that can be combined with teammates, radar towers help track the enemy flag’s location, and there are enough hidden areas in the maps to make flag placement a genuine strategic layer. When a team captures the opponent’s flag, the game enters its final stage: defend the stolen flag for 60 seconds while the other side fights to take it back. Clean concept, tight execution.
The honest truth is that Last Flag has had a rough time building a player base since its April 2026 launch — peak concurrent numbers have been modest, and the developers have been running free weekend promotions as an ongoing effort to get more eyes on it. At $4.99 base price with no battle pass or microtransactions, it’s genuinely worth checking out during this free window. If multiplayer games need players to be fun, and they do, this weekend is your best shot at finding full lobbies.
- Genre: PvP Hero Shooter / Capture The Flag
- Developer/Publisher: Night Street Games
- Steam Review Rating: 73% Mostly Positive (576 reviews)
- Can you finish it this weekend? It’s multiplayer — play as many matches as you want.
- Purchase Discount: None needed — it’s $4.99 at full price.
Jump Space
Jump Space is a four-player co-op PvE game where you and your crew manage a spaceship together, and “manage” is doing a lot of work in that sentence. Between missions, you’re piloting, repairing damage, managing systems, and keeping the ship in one piece. During missions, you’re landing on planets, exploring, salvaging resources, and fighting enemies — then switching back to ship operations as you move to the next objective. Missions have randomized elements so each run plays out differently, and there are no locked classes; anyone can take the pilot seat, handle engineering, or lead field exploration based on what the situation demands.
The 87% Very Positive rating from over 7,000 reviews suggests it genuinely delivers on the co-op chaos promise, and at $19.99 normally (dropping to $11.99 this weekend), it’s one of the better-value co-op games on Steam. It’s the one game this weekend where you can actually “beat” it during the free period — the main mission structure has a completion point — though there’s plenty more to do beyond that.
- Genre: Mission-Based Co-Op PvE Sci-Fi
- Developer/Publisher: Keepsake Games
- Steam Review Rating: 87% Very Positive (7K+ reviews)
- Can you finish it this weekend? Yes — though there’s plenty of additional content beyond the main campaign.
- Purchase Discount: 40% off until September 24 ($19.99 → $11.99)
Which Should You Play First?
If you have a squad ready to go, Sea of Thieves is the obvious first pick — it’s the most social game on the list, the most replayable in a single sitting, and with that 65% discount it’s an easy buy for anyone who gets hooked. Jump Space is the sleeper pick for groups of four who want something more structured with a beginning and end point. Diablo 4 is the safe bet for anyone who just wants a solo or duo experience that they know will be polished and content-rich. And Last Flag is genuinely worth a few matches — the concept is tight, the aesthetic is surprisingly fun, and at $4.99 the barrier to buying is almost nonexistent if you enjoy it.
All four are available through September 21 at 10am PT / 1pm ET. This is a packed gaming weekend in general — Call of Duty: Modern Warfare 4 is still generating buzz from TGS, and Monster Hunter Wilds: Ascendance hype is building — but for free? You can’t really go wrong with any of the four on offer. Just don’t wait until Sunday night to start.
