Are (un)tapped permanents still legal targets for "(un)tap target permanent" effects?

Question

So I noticed that many cards with tap-effects ship with a clause specifying that they can only be used on untapped permanents, such as Earthcraft and Crackleburr.

So here's my question:

Doesn't that imply that, given the right situation, one can legally tap an already tapped permanent?

I'll give an example of the kinda scenarios this is relevant for: Can Tamiyo, the Moon Sage activate her first ability when no untapped cards are around? Or, thinking untap-effects, could I bounce a forest with Scryb Ranger even when there isn't a tapped creature available?

Notice that, unlike the previous batch of examples, the wording on these lacks the clause restricting their use to un/tapped permanents - does that mean that they aren't?

Any kind of clarification would be greatly appreciated here.

Answer 1

If it's a permanent, it's a valid target for "target permanent". Period^[1].

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You cannot untap a permanent that's not tapped.

701.17b To untap a permanent, rotate it back to the upright position from a sideways position. Only tapped permanents can be untapped.

This has consequences^[2], but not for Tamiyo.

609.3. If an effect attempts to do something impossible, it does only as much as possible.

The confusion stems from the fact that players intuitively know they cannot choose to do something impossible. This is indeed a rule.

608.2d [...] The player can’t choose an option that’s illegal or impossible, with the exception that having a library with no cards in it doesn’t make drawing a card an impossible action [...]

However, while you are forbidden from choosing to do something impossible, there's nothing impossible about activating Tamiyo's ability. It's of no consequence that the ability involves actions that cannot be performed if the ability were to resolve immediately after being activated.

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1. As usual, cards can override the rules. For example, abilities such as Shroud, Hexproof and Protection can prevent a permanent from being targeted.

2. You are required to pay a cost completely^{[CR 117.3]}, so a cost that requires you to untap something that isn't tapped can't be payed.

   For example, the untap symbol means "Untap this permanent". Because you can't untap a permanent that isn't tapped, you can't pay the cost of Puresight Merrow's ability when Puresight Merrow isn't tapped.

   For example, If you want to untap a tapped permanent so it can attack, and you use an instant that reads "Tap or untap target permanent.", and someone untaps it in response, you would be force to tap it when your ability resolves (because you can't chose to do something impossible.) That's why that type of ability is phrased "You may tap or untap target permanent."

   For example, If you have an ability whose effect reads "You may untap an opponent's land. If you do, do X.", you can't do X if the opponent has no tapped lands.

Answer 2

You cannot untap an untapped permanent to pay an "untap" cost, exactly like how you cannot tap a tapped permanent to pay a "tap" cost.

107.6. The untap symbol is {Q}. The untap symbol in an activation cost means "Untap this permanent." A permanent that's already untapped can't be untapped again to pay the cost.

However, Tamiyo CAN use her first ability even without any untapped creatures around. This is because it says "target creature", not "target untapped creature". So you can target a tapped creature as a legal target. When the ability resolves, it will first attempt to tap the already tapped creature (which will do nothing), and then the "it doesn't untap..." will still take effect.

In the same way, you can use Scryb Ranger's ability even without any untapped creatures, because you can target a tapped creature. But again, when the ability resolves, it will attempt to tap the already tapped creature, which will simply do nothing.

The key here is that you can never tap a creature that's already tapped, or untap a creature that's already untapped. Attempting to do so to pay a cost is like attempting to pay 1 mana when you have no mana in your mana pool; you can't do it. However, nothing stops you from using a spell or ability that, as part of its resolution, attempts to tap a tapped creature.

Answer 3

You are looking at two different things here: costs and effects. Earthcraft and Crackleburr both require you to tap untapped permanents (or untap tapped permanents) to activate their abilities. If Earthcraft allowed you to tap a tapped creature to untap your a land, then with just one creature you could untap all of your land forever.

For the other two, the tapping or untapping is the effect of the ability. In Tamiyo's case, you pay the cost by adding one loyalty counter and you choose a target. Then, when the ability resolves, the targeted permanent becomes tapped. Similarly, in Scryb Ranger's case, putting the land in your hand is the cost of activating the ability. Even if the creature dies before the ability resolves, the land is already in your hand.