Rules glossary
↑ Parent rule: 107.3 Many objects use the letter X as a placeholder for a number…
107.3k If an object’s activated ability has an {X}, [-X], or X in its activation cost, the value of X for that ability is independent of any other values of X chosen for that object or for other instances of abilities of that object. This is an exception to rule 107.3i.
No sub-rules.