Simple Combos do not have any special requirements. There are three main types of Simple Combos: Hard Combo, Soft Combo and Hybrid Combo.
In a Hard Combo, NFTs are locked in the Combo.
Once a Hard Combo is minted, it is recorded on-chain. Everyone can verify its authenticity by confirming that the original NFTs are locked on the platform.
Hard Combos also allow users to check an NFT's "on-chain life", that is to say, its Hard Combo history.
We would also like to point out that when users sell a Hard Combo, they sell all the NFTs locked in it. Nevertheless, the asking price for a Hard Combo could be higher than the original NFT's. That's because the owner is selling the same NFT in addition to some extra features. Moreover, since people can check the NFT's "on-chain life", over time, the price of a Hard Combo could increase depending on its Combo history and previous ownership.
Hard Combos can be dismantled at any point. When dismantled, the Combo reverts back to the NFTs which were used to mint it.
In a Soft Combo, none of the NFTs is locked.
You can continue using the original NFTs and the Combo NFT without limitations.
Unlike Hard Combos, when users sell Soft Combos, they get to keep the NFTs used to mint it.
In a Hybrid Combo, at least one NFT is locked, and at least one NFT is not locked. With Hybrid Combos, you can create genuine derivative collections.
Just like in the case of a Hard Combo, when users sell a Hybrid Combo, they are also selling the NFT that is locked in it.
Hybrid Combos can also be dismantled at any point. When dismantled, the Combo reverts back to the NFTs which were locked in it.