Here you start with 40 life and play best out of 1.

Your deck must have a LEGENDARY CREATURE as your commander, and no card in your deck may have a manasymbol not found on that commander. (there are 5 Planeswalkers that are allowed to replace your Commander)

Your deck must be exactly 100 card including your commander, and all cards are restricted to one copy except the 11 Basiclands, Shadowborn Apostle and Relentless Rats.

Finally, there is a specific list of cards you cannot play in your deck

https://magic.wizards.com/en/banned-restricted-list

No sideboards are used.