Metadata
Generally, metadata is used to store some information on-chain. While you want to store slow-data like rarity or level, you most likely don't want to store fast-data like HP and durability. The main reason to not store fast-data on chain is someone has to update it and pay for transaction.
For now only 5 types are stored on-chain:
TEMPLATE_ID
All tokens have this attribute, it refers to the item template id in the database
- it can't be created as attribute in Grade mechanic for any template
- can't be changed by any mechanic
Example: 1-2147483647; int4
LEVEL
LEVEL is the default attribute for the Grade mechanic and Discrete feature.
- tokens can be searched by this attribute
- there is page with statistic over this attribute
- can be changed for a price
- this and other attributes from Grade mechanic are displayed on token page
Example: 1-115792089237316195423570985008687907853269984665640564039457584007913129639935; uint256
RARITY
RARITY is the default attribute for ChainLink integration and Random feature.
- tokens can be searched by this attribute
- there is page with statistic over this attribute
- this attribute is displayed on token page
- can't be changed by any mechanic
- it can't be created as attribute in Grade mechanic for templates that contains Random and Discrete features
Example: 0-4; common, uncommon, rare, epic, legendary
GENES
GENES is the default attribute for the Breeding mechanic and Genes feature.
- this attribute is displayed on token page in decoded format
- can't be changed by any mechanic
- it can't be created as attribute in Grade mechanic for templates that contains Genes and Discrete features
Example: 5846006549663894039973362281908193186987844304901; { a1: 4, a2: 1, a3: 3, a4: 2, a5: 1, a6: 5 }
TRAITS
TRAITS is the default attribute for the Collectible mechanic.
- this attribute is displayed on token page in decoded format
- can't be changed by any mechanic
Example: 5846006549663894039973362281908193186987844304901; { a1: 4, a2: 1, a3: 3, a4: 2, a5: 1, a6: 5 }