Limited Resources | Magic: The Gathering
Formats Limited Resources is Legal in
Official Oracle Text for Limited Resources
Players can't play lands as long as ten or more lands are on the battlefield.
Official Rulings for Limited Resources
10/4/2004 : If a player has less than 5 lands, they get to pick and keep all of their lands.
10/4/2004 : You can put lands onto the battlefield using effects, you just can't play lands from your hand as an action.