Kingfish is a constructed format between Peasant and Commander.
Your deck must follow these rules:
- 1 rare card that is your commander
- All other cards follow commanders color identity
- from the rest of your 60 cards, only 5 of them can be uncommon
- so 1 rare (general), 5 uncommons and 54 commons to create a deck.
Then for the game these rules apply:
- Start with 30 life
- Commander starts in your deck not in command zone
- At the end of turn if your Commander is in in the graveyard or exile you may shuffle it to your deck.
read more:
https://mtg.gamepedia.com/Kingfish