Valve suffered the largest asset leak in the company's history when a series of asset repositories for games released in 2016 were put online. The games are Portal, Counter Strike: Source, Day of Defeat: Source, Half Life 2: Episodes 1 & 2, Half-Life 2 multiplayer, and Team Fortress 2.

The leak appears to have originated from an account calling itself WandererLeaker and was initially circulated via Discord; in a Discord chat, Leaker wrote (open in new tab): "I don't care anymore. I also toyed with it for a few years but didn't upload it because every time I was threatened [...]. I'm really sorry. I have no legal binding rights to these files. Not anymore". They later added: "I have been holding these files since 2016."

The leaks are in the form of asset repositories, which are typically a way to bundle up game files for sharing with outside partners. The largest leak of its magnitude is "Team Fortress 2," and diving into this leak will give you an idea of what is being unearthed here. The short version is that almost every asset in this game is a 61 GB package.

"There are tons of maps, models, PSDs, VMFs, everything you've never seen," writes TF2 content creator Richter Overtime (open in new tab). 'When the community is done digesting this (61 GB), there will be nothing else to talk about. This is the last official TF2 content drop you and I will see."

That may be quite a bit of overkill, but there is certainly something here to get excited about. The assets are from 2016 and include content that was cut, content that was released in another form, and assets that were abandoned for whatever reason. There is a skeleton of a raid mode, which was cancelled and repurposed as an element of the Mann Vs. Machine mode. In fact, there are so many prototype maps that they still have not all been dug out.

Others found include a 3D model of Saxton Hale, another bonesaw model, unused animations, several tutorial modes, weapon variations, an unused model of a small three-legged robot, and a spellbook witch based on an older version of Miss Pauling (in new tab open in new tab), and more were found.

Of particular note are a number of green and yellow textures, suggesting that at one point Valve was considering introducing the classic Team Fortress color scheme to both teams.

Most terrifying of all are the level 4 sentries, and if you haven't played TF2, know this: the level 3 sentries will turn you and your team into colorful gibbets over and over again. The fact that this guy has a final form... Yeah, certain things are best left on the cutting room floor.

This leak also includes various taunts that were created but never added to the game or remain unfinished.

The TF2 community is also full of jokers, some of whom are using this leak as an opportunity to post slightly obscure old or community content and say it is part of the leak. This is a sight only a mother should see, a naked spy model, but not from this particular leak (although the detail of the shoes on is great).

Another older leak that is mixed up is a female soldier model (opens in new tab), which is official but the texture is fan-made. The other is an internal pitch, first shared by artist Drew Wolfe in 2017, for female versions of each class to appear in the game (opens in new tab). The idea of an 80-year-old Scottish grandmother demowoman is particularly brilliant: "In particular, the idea of an 80-year-old Scottish grandmother demowoman is fantastic.

This material is just now being combed through by data miners and modders. If you are interested and want to dig deeper in your own way, keep in mind that much of what is written about what an item was intended for or why it was abandoned is speculation. Given the amount of assets TF2 has amassed, a certain amount of waste is inevitable.

The last official update to Team Fortress 2 gave the community the keys to the kingdom (opens in new tab) as Valve focused on adding tools and creator freedom to keep this game alive for years to come. This very informal addendum will no doubt accelerate that, and it is undeniably something of a coincidence that this happened shortly thereafter; whatever the TF2 community does with this, I hope no one makes a level 4 Sentry, because it's a very good thing.

As for the other leaks, they are similar to the above, but on a smaller scale. There is definitely material of interest in the various Half-Life and Portal files, but don't expect anyone to find Half-Life 3 source code in this: it is all bundled assets to be shared with external partners, and therefore, especially sensitive material should have been removed beforehand (and this leak shows exactly why).

I have asked Valve to comment on this massive leak of material.