Take from the forum. Made it cost a bit more and the land enter tapped, this feels like its just restricting what the card's doing though so maybe we can remove one of those?

I'm not a big fan of how variable the power level is here, and I don't like that it probably works best when you don't have many lands in your deck, when that's ultimately what Discovery wants you to do.

This is actually identical to the way I reformulated the card in a recent card contest post, except I made it uncommon. The power level is pretty variable though, that is an oddity about it.

Maybe one way to get more to the point would be to change it to this:

"Exile the top three cards of your library. Until end of turn, you may play cards exiled this way. You may play an additional land this turn." (or some other wording that lets you play any lands exiled).

The idea is to basically have an Act On Impulse that doesn't potentially make exiled lands go to waste - you can both play a land on your turn before casting it, and play lands that it exiles from your library.

I like this version. "Exile the top three cards of your library. Until end of turn, you may play cards exiled this way. You may play an additional land this turn."

Would be quite strong at three CMC though, maybe 4 CMC would be better.

I second that, probably a good change.

Card edited to the new version. I think it can be kept at 3 CMC as a rare personally, given that Act On Impulse is uncommon at 3 CMC and this is multi-colored, I think it's not too pushed as a rare.

I also changed the card name to Explorative Impulse.

Can we develop this to be the uncommon? This seems like a much better fit for the discovery theme than the RG uncommons we have so far.

I prefer this as an uncommon as well. It seems kind of blah as a rare when Act On Impulse is an uncommon. It being green as well as red I feel justifies the extra perk of letting you play an additional land.

Maybe the way to make this viable as a 3 CMC uncommon would be, instead of saying you may play an additional land this turn, it simply says something like: "You may put any number of lands exiled this way onto the battlefield tapped."

This slot is the most contested multicolor one. The altered version of this that I mentioned in the above comment I feel may be the best fit. Otherwise, I prefer World as Will for this slot.