Rules glossary
↑ Parent rule: 709.5 Some split cards are permanent cards with a single shared ty…
709.5e A player who controls a permanent that has one or more locked halves may pay the mana cost of a locked half of that permanent to give that permanent the appropriate unlocked designation. This cost is referred to as an “unlock cost.” This is a special action (see rule 116). A player can take this action any time they have priority and the stack is empty during a main phase of their turn.
No sub-rules.