Each Saga without read ahead has the intrinsic ability “This Saga enters with a lore counter on it.” This ability creates a replacement effect (see rule 614.1c).
October 13, 2023 · Doctor Who
As a Saga without the read ahead ability enters the battlefield, its controller puts a lore counter on it. As a Saga with the read ahead ability enters the battlefield, its controller chooses a number from one to that Saga’s final chapter number. That Saga enters the battlefield with the chosen number of lore counters on it. (See rule 702.155, “Read Ahead.”)
April 14, 2023 · March of the Machine
As a Saga without the read ahead ability enters the battlefield, its controller puts a lore counter on it. (See rule 702.155, “Read Ahead.”)
July 23, 2021 · Adventures in the Forgotten Realms
rule 714.3a not present in this release
January 24, 2020 · Theros Beyond Death
As a Saga enters the battlefield, its controller puts a lore counter on it.
April 27, 2018 · Dominaria
As a Saga enters the battlefield, its controller puts a lore counter it.