What it does
I'm not familiar with a Magic: The Gathering keyword or ability called "Sec." It's possible this is a typo, an abbreviation, or a term from outside the official rules.
A few possibilities you might mean:
- "Sac" — common shorthand for sacrifice, paying a cost by putting your own permanent into the graveyard.
- A specific card with "Sec" in its name.
- A term from a custom or unofficial format.
If you can clarify what you're referring to—or share the exact card or rules text—I'll give you a proper rundown of how it works and how it matters in Commander. I don't want to invent rules for a keyword that doesn't exist, since that would just mislead you at the table.
