A boundary is a limit on what you will accept and what you'll do in response — not a request for the other person's permission. With a narcissist, boundaries won't change them and will often be tested hard, so the key is to make boundaries about your own actions (which you control) rather than theirs, and to expect and plan for the pushback.
Most people think a boundary is telling someone what to do. It isn't. A boundary is a decision about your own behavior: “If X happens, I will do Y.” You can't control whether a narcissist respects it — but you can control what you do when they don't. That's the part that actually protects you.
To someone entitled and low in empathy, your boundary reads as a threat to their control. Expect extinction bursts — the behavior gets worse before it fades — plus guilt-trips, rage, charm, or playing the victim. None of that means your boundary is wrong. It means it's working.
You're not building a fence to change them. You're building one so you can finally breathe on your side of it.
Because the boundary threatens their control, they often escalate first — more guilt, rage, or charm — to get you to drop it. This “extinction burst” is common and usually fades if you hold firm. It's a sign the boundary matters, not that it's failing.
Keep it brief. A short, calm statement is enough. Long explanations invite debate and give a manipulative person material to twist. Your boundary is about your actions, which don't require their agreement.
Then the boundary shifts to reducing access — less contact, gray rock, or no contact — because the only limit you fully control is how much of yourself you make available to them.