The trade-up contract is the one tool inside CS2 that turns skins into a different skin. You put in ten items and you get one back. What comes out is decided by two rules, one for which skin and one for its float. Both are simple once you see them written down, and both are worth knowing even if you never run a contract, because a lot of the low-float items on the market were made this way.
The rules of entry
- Ten inputs, no more and no fewer.
- All ten must be the same rarity tier: Consumer Grade, Industrial Grade, Mil-Spec, Restricted or Classified. Covert skins cannot go in, because there is no tier above Covert to trade up to.
- All ten must be normal, or all ten must be StatTrak. No mixing. Ten StatTrak inputs give a StatTrak output.
- Souvenir items cannot be used. Knives, gloves and agents cannot be used.
- Stickers and name tags on the inputs are destroyed with them.
The output is one skin from the next tier up. Ten Restricted inputs give a Classified. Ten Classified inputs give a Covert. Once you confirm, the ten inputs are gone.
Which skin comes out
The output is drawn from the collections of the inputs. A collection is the set of skins a case or a map drop belongs to, and each skin belongs to exactly one.
The way the draw works, in words: every input is a vote for its own collection. Every skin of the next tier in that collection gets one entry for each vote. Then one entry is drawn at random from the whole pile.
Two things follow from that. A collection with more skins at the next tier fills more of the pile, so it is drawn more often than its share of the inputs would suggest. And if all ten inputs come from one collection, the outcome is one of that collection’s next-tier skins, each with an equal chance.
The client lists the possible outcomes before you confirm. Look at that list. If it contains skins you would not want at any price, those are the likely results.
How the float is decided
The float of the output is not random. It is calculated from the ten inputs, and this is the part that makes contracts interesting for float hunters.
- Take each input’s float and work out where it sits inside that skin’s own float range, as a fraction from the bottom of the range to the top. A skin with the full 0.00 to 1.00 range at 0.20 sits a fifth of the way up. An AK-47 | Redline, whose range runs from 0.10 to 0.70, sits a sixth of the way up at the same 0.20.
- Average those ten fractions.
- Place the result at the same fraction inside the output skin’s float range.
The output float is fixed the moment the contract completes and never changes afterward.
Two consequences. First, the output can never land outside its own range, so a contract into a skin with a high minimum float will never give a Factory New. Second, the fractions are what count, not the raw numbers. Ten inputs that sit near the bottom of their own ranges give an output near the bottom of its range, even if the raw floats of the inputs were not especially low.
Why people craft for low floats
Some skins rarely drop clean because their float range starts high, so clean copies are scarce. A contract lets you choose the inputs, so you can pick ten copies that all sit at the very bottom of their ranges and force an output at the very bottom of its range.
Many of the lowest-float copies of popular skins were made this way. Nobody opened them. Someone bought ten cheap skins with the right numbers and ran the contract. Very low float outputs sell for a premium, and the same is true at the other end: ten inputs at the top of their ranges give a Battle-Scarred output as dark as the skin allows, which some collectors want too.
What a contract cannot do
- It cannot produce a knife, gloves or a Contraband item. The ladder stops at Covert.
- It cannot produce a skin from a collection that none of the inputs belong to.
- It cannot change the StatTrak status. Normal in, normal out.
- It cannot be undone. The inputs are consumed the moment you confirm.
The honest part
The rule for which skin comes out is a draw, and most contracts are worth less on average than the ten inputs cost. That is not a secret. The skins that are cheap to buy as inputs are cheap for a reason, and the outcome pool usually holds more duds than prizes. Anyone who runs contracts seriously does it by studying the collections, picking inputs whose outcomes are all worth having, and using the float rule to make the output clean. Treat it as a craft that takes homework, not as a way to make money.
The skin is a draw. The float is a formula. If you want a specific number, the contract is a tool. If you want a specific skin, buying it outright is usually the cheaper route.
What this means when you buy
A very low or very high float on a common skin is often a contract output, and there is nothing wrong with that. The float is real and permanent. When a listing shows a float that seems too clean for the skin, check the skin’s float range and the exact number in the inspect data, and then price the number on its own terms.
On PrefireSkins every lot shows its exterior and, where the inspect data gives it, the exact float. Whether a copy came from a drop or a contract makes no difference to what you receive.
