The Rule: Each player begins the draft with a Cogwork Librarian face-up in front of them, as if it had been drafted.
one for each player
The Basic Effect: Each drafter begins with an extra-pick "token". As these tokens are used, they re-enter circulation between drafters. Other drafters may then use a draft pick to stockpile another token, effectively saving that pick until better options are present.
Cube designers can include one particular card to make Cogwork Librarian more than just a draft token: Secret Summoning.
Squadron Hawkify
Secret Summoning causes your first copy of Cogwork Librarian to tutor your remaining copies in a manner similar to Squadron Hawk. In a pod of 8 players, there are 8 copies of Cogwork Librarian in the draft pool alongside the 360 cards opened in packs.
The Librarian Rule brings more options to the table, creating a greater sense of agency for drafters. Cube designers may find additional benefits to the rule. Consider the following.
Salvage Distribution Problems: Niche strategies are less likely to be hosed by having multiple key cards trapped within the same pack. This issue historically and disproportionately hinders narrow archetypes (such as RG Storm from MH2). Cogwork Librarian can salvage more loosely supported archetypes that would otherwise be nonviable due to pack distribution.
a common combo, sometimes trainwrecked by having all the pieces packed together
Safe Pick Bias: Experienced drafters often scoop up fetchlands early in the packs, as they are non-committal picks. This draft strategy naturally biases towards 4+ color pile decks, which Cube designers generally do not wish to encourage. Extra-pick tokens reduce the pressure on traditionally safe picks such as fetchlands.
will probably make the deck VS becomes something that will make the deck
Signal Boosting: Drafters can send and read signals sooner in the draft. Upon receiving an early pack absent of a color but with a freshly spent Librarian, a drafter may be able to secure an open lane sooner.
alternatively, strong cards sitting next to Librarian can indicate drafters have committed elsewhere
Secret Archetypes: Secret Summoning with 4+ Cogwork Librarians can enable new and powerful decks. What happens when you turn an artifact Hill Giant into a Squadron Hawk? How does this package interact with Big Mana decks? Sacrifice decks? Artifact decks?
only in cube
Secret Considerations: In relation to the previous point, draft choices with Cogwork Librarian gain additional nuance when Secret Summoning is in the cube. The ubiquity of the Librarian must be balanced with caution of the Secret Summoning drafter acquiring a critical mass.