MTG Salvation

I got in a debate over what actually happens when Steward of the Harvest exiles a basic land. For the sake of explanation, let's say it exiles a basic Forest land. We will also say there's three 3/3 beast creature tokens in play just to have some creatures to affect. So what happens if Steward of the Harvest exiles a basic Forest land? Can the beast tokens tap for green mana, or do they not get any ability? Please explain either way.

For the record, I believe they don't get any ability from the basic land, because the ability to tap a Forest for green is linked to the forest type. The beast tokens aren't forests, so they can't tap to add green. I ran across this same issue when building Myrkul, Lord of Bones. I found out that if I animate a basic land and sacrifice it, Myrkul, Lord of Bones would make a copy of it, but since that copy is only an enchantment, it no longer has the ability to tap for mana. If the previous case with Steward of the Harvest is different, please explain how it's different.

The Forest card in exile inherently has the ability "TAP: Add G." Since that card is a land card and has an ability, so does Steward of the Harvest.

It doesn't matter that the Steward isn't a forest or a land. The exiled card is.

When Myrkul makes something lose all other card types than enchantment, it makes the permanent not a land. And when something is not a land, it doesn't have any land types, so it's not a Forest. And when it's not a Forest, it doesn't have "{Tap}: Add {G}".

Steward of the Harvest can give the mana ability to creatures because the exiled Forest card does have that ability.

I don't know why, but I was expecting more details like rules references or something. When I searched Google, the AI in the Google search engine said it doesn't work. I dug around the rules and what I find says it doesn't work. Then a random person on Facebook said it does work. I'm gonna need a bit more to go on here.

So in the context of the AI search on Google. It said that the basic land has no abilities printed on the card itself. Because of that, Steward of the Harvest doesn't see any abilities, and the creatures get no abilities. The way I'm understanding it, it's similar to how the game doesn't care if you put a creature with extort in a black and blue commander deck. The Orzhov hybrid symbol is in the reminder text of extort, not on the card itself. Just as how a Forest has no text box, and has reminder text that it taps for a green (on some versions). I just come to assume that reminder text is never treated as actual text, so Steward of the Harvest shouldn't be able to see it either.

Anyway, please understand. I'm not trying to be rude, but a halfhearted explanation won't cut it here. I'm still not convinced. Like, do I have to contact Wizards to try and get an answer from them? I'm joking of course.

I think you're mistaken about this. Forests do not have an ability "As long as ~ is a forest, it has "T : add G"" that would only work when it is on the battlefield and wouldn't work when it is elsewhere. If it was the case, you would be right, the steward would not give the ability to produce green mana because the exiled card's ability would not work unless explicitely said. Rather, it is the rules that give all forest objects the ability to produce green mana, and it does not require the forest card to be on the battlefield.

Quote from Rule 305.6 »

The basic land types are Plains, Island, Swamp, Mountain, and Forest. If an object uses the words “basic land type,” it’s referring to one of these subtypes. An object with the land card type and a basic land type has the intrinsic ability “{T}: Add [mana symbol],” even if the text box doesn’t actually contain that text or the object has no text box. For Plains, [mana symbol] is {W}; for Islands, {U}; for Swamps, {B}; for Mountains, {R}; and for Forests, {G}. See rule 107.4a. See also rule 605, “Mana Abilities.”

Here's what I was able to find to explain this. So first we need to prove that a basic land always has that activated ability for Steward to see and grant to other creatures. For this we start with CR 305.6. The basic land types are Plains, Island, Swamp, Mountain, and Forest. If an object uses the words “basic land type,” it’s referring to one of these subtypes. A land with a basic land type has the intrinsic ability “{T}: Add [mana symbol] to your mana pool,” even if the text box doesn’t actually contain that text or the object has no text box.

Note that it doesn't specify permanents, so this would apply to the card in all zones. We can back that up further with the Gatherer rulings on Zirda, the Dawnwalker. (Permanent cards are artifact, creature, enchantment, land, and planeswalker cards. Land cards with basic land types have intrinsic activated mana abilities associated with those types.) If basic lands didn't have an always-present activated ability, you couldn't include them in a Zirda deck.

Basic lands also do not have reminder text. Reminder text wasn't introduced until Mirage. They are simply sometimes lacking explicit rules text. The original basic lands all had printed rules text.

So Steward looks at the exiled basic, sees that it has its intrinsic Forest subtype activated ability, and gives that to the creatures.

As for Myrkul, the reason it's different is because we are removing a card type.

205.1a Some effects set an object’s card type. In such cases, the new card type(s) replaces any
existing card types. Counters, effects, and damage marked on the object remain with it, even if
they are meaningless to the new card type. Similarly, when an effect sets one or more of an
object’s subtypes, the new subtype(s) replaces any existing subtypes from the appropriate set
(creature types, land types, artifact types, enchantment types, planeswalker types, or spell
types). If an object’s card type is removed, the subtypes correlated with that card type will
remain if they are also the subtypes of a card type the object currently has; otherwise, they are
also removed for the entire time the object’s card type is removed. Removing an object's subtype doesn't affect its card types at all.

So Myrkul gives you an enchantment token of the land, but strips it of its land type and corresponding subtype, thus removing the ability to tap for mana.

305.6. The basic land types are Plains, Island, Swamp, Mountain, and Forest. If an object uses the words “basic land type,” it’s referring to one of these subtypes. An object with the land card type and a basic land type has the intrinsic ability “{T}: Add [mana symbol],” even if the text box doesn’t actually contain that text or the object has no text box. For Plains, [mana symbol] is {W}; for Islands, {U}; for Swamps, {B}; for Mountains, {R}; and for Forests, {G}. See rule 107.4a. See also rule 605, “Mana Abilities.”

From this rule, we see that an object with the land card type and the basic land type Forest has the intrinsic ability "{T}: Add {G}".
The exiled Forest card is an object with the land card type and the basic land type Forest, since it's written on the card. (Forest)
The ability "{T}: Add {G}" is an activated ability because it has a colon.
The steward gives "{T}: Add {G}" to the other creatures because it is an activated ability that the exiled Forest card has.

Ok, this was a nearly perfect explanation. Thanks for clearing this up.