Rule 714.4 · Saga Cards

If the number of lore counters on a Saga permanent with one or more chapter abilities is greater than or equal to its final chapter number, and it isn’t the source of a chapter ability that has triggered but not yet left the stack, that Saga’s controller sacrifices it. This state-based action doesn’t use the stack.

Other rules in this chapter

Ask the judge Pro

The life counter has an AI judge that answers your play citing the exact rules. It is part of Gatewatch Pro; the rules, Oracle text and rulings stay free.