Radha, Heart of Keld

Text:

As long as it's your turn, Radha, Heart of Keld has first strike.
You may look at the top card of your library any time, and you may play lands from the top of your library.
: Radha gets +X/+X until end of turn, where X is the number of lands you control.

Rulings:

• 6/23/2020 Radha doesn’t allow you to play additional lands.
• 6/23/2020 Radha lets you look at the top card of your library whenever you want (with one restriction; see below), even if you don’t have priority. This action doesn’t use the stack. Knowing what that card is becomes part of the information you have access to, just like you can look at the cards in your hand.
• 6/23/2020 If the top card of your library changes while you’re casting a spell, playing a land, or activating an ability, you can’t look at the new top card until you finish doing so. This means that if you play a land from the top of your library and it has a replacement effect that requires you to make a decision (such as that of Temple Garden), you must make that decision without knowing the next card of your library.
• 6/23/2020 The value of X is determined only as Radha’s last ability resolves. Once that happens, the value of X won’t change later in the turn even if the number of lands you control changes.