Not A Bug Barrowgoyf doesn't properly trigger when library is less than power.

[fishduggery]

Hi Daybreak team,
I was playing a match and had 2 cards in library, and hit my opponent with a 4/5 Barrowgoyf. The ability triggered, but did not give the usual Yes/No options for the mill. Instead the ability just resolved and does nothing.
My understanding of the rules is even if you have less cards in library than the Barrowgoyf's power, you can say yes and mill all your remaining cards.
Game id is 898024018 and the bug occurred twice on consecutive turns, my turn 5 with 2 cards in library and my turn 6 with 1 card in library.
Thanks for your attention, I really appreciate all the hard work you've put into improving the client <3

 

[Neo001992]

Barrowgoyf itself doesn't have a direct ruling yet, but other cards with similar 'may mill' abilities do have rulings supporting that you can't choose to mill more cards than you have in your library if it is a choice.

General ruling: "If a player is instructed to mill more cards than they have in their library, they put all of the cards in their library into their graveyard. On the other hand, if a player is given a choice to mill more cards than they have in their library, they can't choose to do so."

Specific references to a similar effect:
Druidic Ritual {2}{G}
Sorcery
You may mill three cards. Then return up to one creature card and up to one land card from your graveyard to your hand. (To mill a card, put the top card of your library into your graveyard.)

• If you have fewer than three cards in your library, you can't choose to mill any cards this way.(2022-06-10)

Hedge Shredder {2}{G}{G}
Artifact — Vehicle
Whenever Hedge Shredder attacks, you may mill two cards.
Whenever one or more land cards are put into your graveyard from your library, put them onto the battlefield tapped.
Crew 1 (Tap any number of creatures you control with total power 1 or more: This Vehicle becomes an artifact creature until end of turn.)
5/5

• If your library contains one or fewer cards when Hedge Shredder's first ability begins to resolve, you can't choose to mill two cards.(2024-09-20)

 

[Torbin]

Tag applied: Not A Bug

Following the rules about milling, if the user is given the choice to mill more cards than are left in the library, as in Barrowgoyf's case, he cannot proceed with the action.

701.13b A player can’t mill a number of cards greater than the number of cards in their library. If given the choice to do so, they can’t choose to take that action. If instructed to do so, they mill as many as possible. Similarly, the player can’t pay a cost that includes milling a number of cards greater than the number of cards in their library.