Since they (Darkslick Shores, Blackcleave Cliffs, Seachrome Coast, etc) come into play tapped unless you control two or fewer lands. My question is, do you control the Darkslick Shores (or whichever of those lands) when it checks for how many lands you control? So, if I already have two lands on the board and on turn three play a Darkslick, does it come into play tapped or not?
No it won't count itself as it's entering the battlefield. As long as before it's on the battlefield there are 2 or less lands on the battlefield it comes into play untapped.
Since they (Darkslick Shores, Blackcleave Cliffs, Seachrome Coast, etc) come into play tapped unless you control two or fewer lands. My question is, do you control the Darkslick Shores (or whichever of those lands) when it checks for how many lands you control? So, if I already have two lands on the board and on turn three play a Darkslick, does it come into play tapped or not?
Read the card carefully. It says "two or fewer other lands". So it will never count itself. You can have the scars duals enter as the third land and they'll still be untapped.
Two Score, Minus Two or: A Stargate Tail
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