Few could have predicted a resurgence for Left 4 Dead 2 in 2020, but the cooperative first-person shooter is nevertheless seeing new life. That's in large part due to the release of The Last Stand update, a massive content drop made entirely by the Left 4 Dead 2 fan community. Valve is putting its full support behind The Last Stand update, even going so far as to make the game more accessible. Left 4 Dead 2 is free this weekend, and those who play it can buy the game for a discount afterward.

The free weekend has already begun, for those hoping to jump into Left 4 Dead 2 as soon as they can. The full game is free, including Left 4 Dead 2's Survival mode, its competitive Versus mode, 4-player co-op, as well as its single-player campaign using AI teammates. Anyone interested will be able to try out the game to see if it's something they want to spend more time with until Monday, September 28 at 10:00 a.m. PT.

Alongside the free weekend, Valve is offering Left 4 Dead 2 at a steep discount of 80 percent off on Steam. Left 4 Dead 2 typically costs just $9.99, but this weekend it is available for just $1.99. Those interested can also get a Left 4 Dead combo bundle, which includes both the original Left 4 Dead as well as its sequel, for $8.98 — which is 55 percent off its full price. This sale also ends Monday at 10:00 a.m. PT.

Those who already own Left 4 Dead 2 have a reason to go back and play. The Last Stand update has a ton of new content, including an expanded campaign so that the Survival map now has a proper route to be completed. Survival also has 26 new environments to fight it out in. Four new Scavenge arenas have also been added, and there are two new melee weapons: The Shovel and Pitchfork.

Outside of those big content additions, the community has also done work polishing up Left 4 Dead 2. That includes new animations for player characters, PvP enhancements, UI improvements, and all manner of bug and exploit fixes.

For a game released in 2009, seeing this much work put into a fan-driven content pack is an achievement. Not only is the game receiving a substantial update, but players are flocking back in numbers that it hasn't seen in years thanks to the Left 4 Dead community, with Valve's support. Valve's games tend to bring communities together in similar ways, whether it's Left 4 Dead, Dota 2, Team Fortress, Counter-Strike, or others.

Left 4 Dead 2 is available now on PC and Xbox 360.