Is Basalt Monolith a 1-card infinite combo with no payoff?

Can't Basalt Monolith go infinite with itself? No payoff or practical use, but it's a one card infinite?

• What are you unsure about here? Do you want to know how the abilities function? Or how loops work in the game? Or something else? – murgatroid99 Oct 28 '19 at 17:54
• Just want to make absolutely sure that you can just untap Monolith with the 3 colorless from it's first ability. Thought i remembered errata somewhere that said you can't, but can't find it. Mostly asking to convince a friend. – CollinB Oct 28 '19 at 17:55
• @CollinB, can't find the exact language, but this article talks about it a bit: magic.wizards.com/en/articles/archive/latest-developments/… – CALEB F Oct 28 '19 at 19:15
• @CALEBF Do you mind if I add that information to my answer? – murgatroid99 Oct 28 '19 at 20:11
• @murgatroid99 Sure, go ahead! – CALEB F Oct 28 '19 at 20:23

Yes, you can tap and untap Basalt Monolith arbitrarily many times, alone, with no other benefit.

The current text of Basalt Monolith's activated abilities is as follows:

{3}: Untap Basalt Monolith.

The first ability adds three mana, and the second ability costs three mana of any type, so you can use the mana produced by the first ability to activate the second ability. Activating both abilities in order results in the game returning to the same exact state it was in before either ability was activated, so you can immediately do the same thing again.

The relevant rule for voluntary infinite loops, rule 721.2a says this:

At any point in the game, the player with priority may suggest a shortcut by describing a sequence of game choices, for all players, that may be legally taken based on the current game state and the predictable results of the sequence of choices. This sequence may be a non-repetitive series of choices, a loop that repeats a specified number of times, multiple loops, or nested loops, and may even cross multiple turns. It can’t include conditional actions, where the outcome of a game event determines the next action a player takes. The ending point of this sequence must be a place where a player has priority, though it need not be the player proposing the shortcut.

Like with any infinite loop, you can announce that you are activating Basalt Monolith's first ability and then using the mana to activate the second ability any specific number of times.

A 2006 article on the Wizards website describes some previous power-level errata to Basalt Monolith that prevented this loop from working:

This card had textbook power-level errata previously; it basically said “you can't use Basalt Monolith to untap itself.” I'm not sure if this clause was invented to stop combos with Power Artifact or the old wording of Relic Bind, but either way it was bad news. It is removed, and Power Artifact fans across the globe can rejoice!

• Alright! That was the text I was referencing, but if it was removed, hooray! – CollinB Oct 29 '19 at 11:34
• There is a card called Elvish House Party that you could either nerf or buff with this card by using it in a loop until it is what ever time you desire. – Q Paul Oct 31 '19 at 11:46
• @QPaul You don't need game actions to waste everyone's time. Just hold priority whenever. – Caleth Nov 1 '19 at 15:28
• In both cases that is considered slow play, which is illegal in tournaments and impolite in most other situations. – murgatroid99 Nov 1 '19 at 16:17

Yes, you can repeat this action as often as you like (which is different from 'infinite times'): you must declare how often you are activating these abilities upfront.

You need another card (e.g. Crackdown Construct) to actually profit from it. More 'single card infinite' cards exist, see the answers to my question Are there any Magic cards capable of generating loops alone?

• Mesmeric Orb empties your library if you're the one doing the combo. Which might also be useful, but requires more finesse to exploit. – Arthur Oct 28 '19 at 20:06
• @Arthur thanks for catching that. I misremembered, and earlier today Gatherer was in maintenance mode. – Glorfindel Oct 28 '19 at 20:08

Yes, this is currently legal* and there is no direct payoff to using the Monolith to untap itself, with no other cards that interact with it, the idea of the card was to give you mana in advance that you would pay for later. There are ways to make this give a benefit, based on how Basalt Monolith works that benefit would most likely be extra if not infinite mana.

Cards that can make this combo create benefit:

• Power Artifact - Infinite colorless mana, since this aura makes the enchanted artifact cost less, letting you tap to gain and untap for , netting and this is infinitely repeatable.
• Kurkesh, Onakke Ancient - This lets you copy the untap ability for - you can tap it again between the resolution of the two untap abilities, gaining for every spent - effectively turning into - repeatable as long as you have red mana - with something like Skyshroud Elf you can use some of the gained as a source of red - leaving you an infinite combo again with a profit (infinite , and/or in this case)
• Crackdown Construct - This one cares about activating abilities that aren't mana abilities. The first ability of Basalt Monolith, tap to gain three colorless, is a mana ability, but the second, pay to untap Basalt Monolith, is not - this combo that is mana neutral would grow the construct to whatever size you decide to stop at, letting you attack, block or fling an arbitrarily large creature.
• Wake Thrasher - this one is similar to the construct, but it cares about the number of untaps, each iteration of the combo gives wake thrasher +1/+1 until end of turn because Monolith is untapped in the combo.

There are other cards that can interact with this combo, but these are generally considered negative results, though with certain strategies and other cards involved can be exploited:

*Previous errata prevented using the mana from Basalt monolith from untapping itself - it would have been theoretically possible to pass this mana through a filter, like the Skyshroud Elf mentioned before, to use it to untap the monolith even while this errata was in place.