You may play an additional land this turn. Draw a card.
"Do not be afraid!" said Gandalf. "For you are not going like Frodo to Mordor, but to Minas Tirith, and there you will be as safe as you can be anywhere in these days."
2017-03-14
Explore's effect allows you to play an additional land during your main phase. Doing so follows the normal timing rules for playing lands. In particular, you don't get to play a land as Explore resolves; Explore fully resolves first and you draw a card, perhaps a land you'll play later.
2017-03-14
If you somehow manage to cast Explore when it's not your turn, you'll draw a card when it resolves, but you won't be able to play a land that turn.
2017-03-14
The effects of multiple Explores in the same turn are cumulative. They're also cumulative with other effects that let you play additional lands, such as the one from Urban Evolution.