Uh I don’t really play other card games but in Magic it’s usually 40% of your deck. Lands are your main mana source, followed by artifacts and creatures (but other types of cards can produce mana as well). Usually your best best is to try to get the most mana per turn so you can play more spells and abilities. You are only able to lay one land at a time but lands work in a variety of ways and even have their own abilities. Some lands can buff you creatures, be fetched by other cards, produce multiple types of mana, produce more than 1 mana, and even become creatures themselves. One deck style called TRON is able to get 7 colorless mana by turn 3 by combining the abilities of three different lands. Magic relies on proper deck construction, good first hand, good mulligans and a understanding of the cards you are playing.