There have been multiple times in Team Fortress 2 history that have seen exploits which allowed players to duplicate items in-game. This is a big deal because items have monetary value. TF2 players have mixed feelings on these items—since there are methods to check if an item is duplicated, you can easily investigate these items before you trade for them. Some strong opinions are being voiced from both sides on whether these items should be allowed to continue to exist or not.

A short side story

Let’s step out of the TF2niverse for a minute. For this story, let’s consider an “X”-brand MP3 player that has a serial number engraved on it by the manufacturer. This particular MP3 player is generally accepted to be valued at $100 because it is stylish, collectable and plays MP3s.

You are Gentleman “A”. You have a $100 bill with a serial number on it. With your $100 bill you can, and do, buy an “X” Mp3 player. During this transaction, it is recorded on public record that your specific $100 bill was traded for this particular MP3 player. At some point after you purchase your MP3 player, X stops selling them. Because it is still stylish, collectable and functional, you can easily resell your MP3 player to Collector C, Teenager T or anyone else for at least the $100 you paid for it at any time.

Now let us use our imagination a bit more. Scumbag S finds a way to take an X and turn it into two identical “X”-brand MP3 players—identical in the sense that they are both still just as stylish, play MP3s perfectly and have the same serial number (suspend reality for a moment and think more ‘out of thin air’ magic, not foreign knock-off exact replica). Scumbag S starts using this trick to mass produce the “X” and selling the duplicates, dupes for short, for $75. Dirtball D sees what Scumbag S did there and starts doing the same but undercutting further and selling the dupes for $65.

Collector C will not buy the duplicated MP3 players because he wants only originals. He can look at the public records and verify the originals before he buys them. Teenager T does n0t care about duplicates. She just wants to listen to MP3s.

Now you are unable to resell your MP3 player for the $100 you paid as easily because the demand is split. There are quite a few teenagers who just want to listen to MP3s and pay as little as possible to do so. You have to now advertise your MP3 player as non-duped and deal with all the teenagers telling you that it’s the same as a dupe and not worth $100. It becomes frustrating trying to even locate a buyer like Collector C who still sees your X’s value at $100. Because supply goes up with the duplication and demand goes down with each teenager who buys it, the overall value of the X plummets by 50%.

Now let us introduce into the mix a little “X”-brand magic. It comes to their attention what is going on and they flip a switch, causing all duplicated MP3 players to disappear and banning anyone who ever bought or sold a duplicate MP3 player from ever buying or selling anything ever again. What effect does that have on our little ecosystem here? Well, you being the Gentleman, you still have your MP3 player, but may not be able to sell it for the $100 you paid for it even if you wanted to. Scumbag S and Dirtbag D are comfortable on their piles of cash from selling dupes yet are stuck with any originals they had without the ability to ever sell them again. Teenager T is outraged, being down both the duplicate MP3 player and the $65 she paid for it. Collector C laughs at Teenager C but is a bit miffed at Scumbag S and Dirtball D because now there are less MP3 players on the market.

What does this have to do with TF2?

Obviously, this was the story that has already played out in the TF2niverse. The MP3 player is Max’s Severed Head, “X” brand is Valve and the characters are different classes of TF2 players. You, Gentleman A, are a player who acquired your Max from purchasing a game on Steam and were not interested in selling it. Scumbag S and Dirtball D are dupers and scam artists. Collector C represents TF2 collectors and Teenager T being the players who just wanted a hat because they liked the hat. The “X” brand magic mentioned at the end of the analogy was an exaggeration of what may still come to pass. Valve could indeed delete the duplicated hats and trade ban anyone involved in creating, trading and/or owning them.

Max’s Head was never rare by most definitions, but it was generally accepted as currency for larger trades, giving it value. At one point it could be easily sold for upwards of $80. Then the duping began. An exploit in-game allowed players to make enough duped Max’s Heads that the value fell tremendously. Level 1 and 7 were the worst cases of this, to the point that educated traders still shy away from doing business with Heads with these levels. Other valuable items such as Unusuals have also been duped, though not to the extreme of Max’s Head. Even after an exploit like these are fixed, the economy is still affected due to the new supply of dupes. Wary traders cause lesser demand, and while there is always the possibility of the items disappearing and players getting the ban hammer, at least one Valve employee stated on the Steam Users Forum earlier this year that Valve does not plan to further delete any dupes.

So…. Everything is cool now, right?

Nope. Just within the last week another duplication bug popped up. This one involved gifting an item with in-game Gift Wrap and a lot of Unusual Hats were duplicated before the exploit was patched. A lot of players have been VAC banned for this exploit but some of the hats may have gotten out of their backpacks before then. Because of the nature of how Gift Wrap works, these particular items were tagged with “Gifted by: Player name” in the description of the items. Unfortunate players that used Gift Wrap to ‘sign’ their Unusual or for whatever reason gifted the hat to another player in the past should still be able to be verified by looking at the history of the item. We are left with a flag that may indicate a duplicate, but is not definitive.

Educate Yourself

All TF2 items have a unique item (serial) number and the history of the items is recorded in vast item databases (both private and public). You can view some third party histories of items on websites such as TF2items.com by clicking on the item in a backpack. These records are by no means perfect, for many reasons. They are second-hand stats that indicate when the site found the item, not when the item came to be. Anything traded to or from a private backpack loses links in its chain, and many items existed before the records began, so they have acquired dates far past their origin. That all said, you can still use the information to look into items that you are interested in trading for. For example, let’s look at my Anger #91. You can see that the first person to acquire it did so on March 4th, 2012. That is consistent with the fact that the Anger was added to the game on August 3rd, 2011. There is a couple days between the next player to own it and about a week in between when they traded it to when it shows I became the owner. This is understandable, because again, these dates are when this site found the item change, not when it took place.

Valve has taken a few actions in response to the first few major duplication exploits, putting some further flags on these items. They have wiped some item histories, reset some item numbers and deleted some items altogether. While these should be taken into consideration when viewing these items, they should not necessarily be taken as definite indications of dupes. An example of this is if an item has no trading history and the acquired date does not match with when the owner should have received it (TF2items.com’s data starts around June 5th, 2011), it may be a dupe with a wiped history—but the player may also have had their backpack private until after that date. If the history shows the same player twice in a row with the exact traded/acquired date and time, or there are two entries with the same item ID, these are strong indications of a duplicated item. An indication for Max Head specifically is that the hats are old enough that they should only have an eight digit item number. If it has a nine digit number, it’s probably duped.

You can also look into a player’s status in the TF2 community. A great site for this is SteamRep. You can take a player’s profile URL and drop it in the search there, and a very informative summary of that player is displayed. If a player has been banned from a popular trading site for scamming, it will show up here. It will also show you if any of the player’s friends are scammers.

Do your homework

What it boils down to is this: If you are going to do high-level trading in TF2, use the tools that are available to research the items and the players you are trading with before you trade. The time spent is worth it, considering what could happen. Don’t be the teenager not caring about the dupes because Valve can—and there is always the slight chance that they will—delete your duped item at any time. Even worse, you could be trade or VAC banned for being involved with a scammer. Valve’s hammer hits hard, and they never accept ignorance as innocence.