Land

Lands represent locations under the player's control, most of which can be used to generate mana. Because mana is needed to use almost any card or ability, most decks need a high number of mana-producing lands (typically between 33-40% of the total deck) in order to function effectively.

Playing lands
Lands are played on the player's own main phase, when the stack is empty, and only once per turn (though there are spells that can alter how many lands you can play a turn, like Exploration). Playing a land is not like playing a spell; it is a special action that does not use the stack and does not require passing priority in order for it to resolve. When a player wants to play a land and has the opportunity, they simply put it into play. Likewise, the mana abilities of lands do not use the stack, and cannot be responded to. Although many lands generate specific colors of mana, lands are colorless on their own.

Flavor
Brady Dommermuth explained the flavor behind the playing of lands in a Magic duel:

"The basic idea is that a mage must first create a bond to the land through some kind of ritual. Whether the mage actually needs to visit the land is an open question. Maybe some lands are so mana-rich or renowned that mages can create a connection to them from across space, time, or even across planes. In any case, once a mage has established a bond to a given place, they can manifest that bond by concentrating on it, then channeling the mana from the land into themselves for spellcasting.

"Perhaps this bond is abstract and only in the mage's thoughts, but we've also thought about ways to represent the bond visually, such as with 'mana globes' that float around a mage. The mage would create a small mana globe - roughly baseball-sized - that is a magical manifestation of his/her connection to a given land. Then the mage could literally 'tap' the mana globe to draw its power into themselves. The mana globe would then slowly regenerate until it was ready to be siphoned again. The bond could also be represented at the site of the land, such as with a totem or magical sigil that 'marks' the mage's bond to it.

"One recent development in this area has to do with legendary lands. It used to be that any unique place would be considered legendary for card purposes, whether it was a single structure or an entire city. We decided recently that unique places should be able to accommodate more than one mage's bond. Theoretically, that means you could start seeing more unique places on nonlegendary land cards. This doesn't mean we won't print legendary lands anymore; such lands will simply be conceived as places that can support a bond with only one mage."

Subtypes
The subtype for lands is called land type and is exclusive to lands.

Friendly to lands
Green is the color that loves lands the most, but every color loves its own basic land type.

These effects are not found often, but they are also both in green's slice of the color pie.
 * Play extra lands

Lands matter
"Lands matter" is a major mechanical focus of the Zendikar block, the Battle for Zendikar block, and the Zendikar Rising set. Two keywords that play into "lands matter" are Landfall and Awaken.

Land tokens
The creation of basic land tokens is a mechanic that appears on test cards in the Mystery Booster set (Generated Horizons). However, it was earlier stated that land tokens are a failed experiment. They are tricky because you're constantly tapping them and the opponent has to monitor the tapped state.

Another easy way to generate Land Tokens of any kind is by casting Mythos of Illuna, as it can create a copy of any permanent. Finally, another easier way to create a land token is by giving to the land another type, usually creature, and creating a copy of the land by following the rules of the gained type. However, keep in mind that token lands created this way do not inherit the new abilities or types that the land gained, as explained in Comprehensive Rules: undefined