How many non basic lands are allowed in a deck?

Related questions

1. How many cards should I have in my magic deck?
2. Is core set 2019 standard legal?
3. Who is the first magician in the world?
4. How is MGMT pronounced?
5. What does it mean when someone calls you boo?
6. What is the meaning of a Black Lotus?
7. Is MTG Arena pay to win?
8. Where did magic originate from first?
9. How many Black Lotus cards exist?
10. Is MTG Arena free?

Tags

1. #restriction
2. #basic
3. #rules
4. #nonbasic
5. #lands
6. #magic