Modern wedding guest list etiquette, and where the old rules genuinely don't apply anymore

A lot of guest list etiquette advice is inherited from an era with different norms around cohabitation, blended families, and who traditionally pays for what. Some of it still holds. A meaningful amount of it doesn't, and treating all of it as fixed rules rather than defaults you can adjust causes more stress than it solves.

What's changed

Plus-ones for every single guest regardless of relationship status used to be closer to a default expectation. Now, limiting plus-ones to married couples, engaged couples, and long-term partners is widely accepted, as long as it's applied consistently across the whole list rather than case by case, which is where the actual arguments start.

What hasn't changed

Whatever policy you set (on plus-ones, on children, on evening-only guests) still needs to be applied evenly. The version of guest list etiquette that reliably causes offense isn't the policy itself, it's an inconsistent one, where some people get an exception and others don't, without a clear or communicated reason.

The B-list question

Keeping a second tier of invitees to send invitations to as regrets come in from the first round is common practice and not considered rude by most modern etiquette standards, as long as it's timed early enough that B-list guests still get a reasonable amount of notice, not a three-week-out invitation that makes the order obvious.

Declining an invitation to someone else's wedding

This one hasn't shifted much: respond by the requested date, don't ask to bring someone who wasn't included on the invitation, and if you're declining, do it without an extended explanation. "We won't be able to make it, but we're so happy for you" is a complete, appropriate response.