# Card Minting/Burning

ERC404 allows for endless possibilities for minting new non-fungible assets, whilst keeping the token supply limited. (i.e. 100k $JUTSU tokens in supply equates to 100k unique Jutsu Cards at any point in time).

### Card Minting

Typically, the ERC404 specification mints an non-fungible asset to ensure that the amount of assets is reflected by the number of whole tokens. The mechanism for minting Jutsu Cards is similar for $JUTSU.

Jutsu Cards are generated based on a weighted probabilistic algorithm when the following criteria are met for each wallet:

1. Wallet needs to hold more than 1 whole $JUTSU token for a Jutsu Card to be minted; and
2. Perform the following action(s) to trigger a re-roll: 
   * Purchased or re-purchased at least 0.5 $JUTSU tokens via the $JUTSU Liquidity Pool (LP) on dojo.trading.
   * Re-rolled via the site gallery where rolls are triggered without LP purchases and fees go directly to Jutsu World

It is possible to obtain an invalid card in $JUTSU should these conditions not be met. Invalid cards may be easily resolved by using the re-roll mechanism on the site gallery.

### Card Burning - (FILO)

Depending on the implementation of the particular ERC404, burns are applied on either the latest 2 NFTs or the earliest 2 non-fungible assets that the token collection has come to represent.

In the case of Jutsu World, our implementation is based on a FILO Card Burning Mechanism.

> Example
>
> Say Wally starts with an empty wallet and buys 3 $JUTSU, his bag of $JUTSU would then represent 3 Jutsu Cards. Let's assume the order of these NFTs from the first token to be Card A, Card B, and Card C.
>
> If the implementation of the ERC404 is First in First Out (FIFO) and Wally sells 1 $JUTSU, then Card A would be burnt, leaving only Card B and Card C. However, if the implementation of the ERC404 is First in Last Out (FILO)
>
> However, if the implementation of the ERC404 is First in Last Out (FILO) and Wally sells 1 $JUTSU, then Card C would disappear leaving only Card A and B.
>
> Since Jutsu World adopts a FILE Card Burning Mechanism, Card C would be burnt.

### Re-Rolls/Re-Mint

Typically, re-rolls/re-mints are achieved by simply selling a fraction and then buying back the fraction to trigger a Burn and a Mint. Depending on the ERC404 implementation, the user may also lock particular assets so that the Burn is targeted.

$JUTSU implements all of the above, and therefore actions typical to other ERC404 are available to the user. 

However, $JUTSU has also implemented a direct re-roll/re-mint that does not rely on triggering Burn/Mints via a Sale/Purchase, and instead by interacting with the primary contract directly. We belive that this saves the user the hassle of locking, and affords him a superior re-rolling experience.