Land Equilibrium | Magic: The Gathering
Formats Land Equilibrium is Legal in
Official Oracle Text for Land Equilibrium
Official Rulings for Land Equilibrium
10/1/2009 : If an opponent puts a land onto the battlefield under his or her own control, he or she may sacrifice that same land. The player won't be able to tap that land for mana before sacrificing it.
10/1/2009 : If a land that would enter the battlefield has its own "If [this land] would enter the battlefield" replacement effect, the player who will control that land chooses which replacement effect to apply. After applying one, if the other one would still be applicable, it's then applied.