Adult only. Private by design.
What a maybe means on a party invite

A maybe does not hold a chair. The host plans for the people who said yes.
The short answer
If you are not sure, say maybe, and say when you will know. A maybe is not a yes, and it is not a seat. The host does not save the night around it.
Your host invites friends. The host invites friends they'd love to have there. One private link per couple. The link goes to people they want there, and a maybe still has to become a yes before you are on the list.
Adult only. Private by design. You confirm you are 18 or older. The host still checks you in. A maybe in a text is not a check-in at the door.
Saying yes to the invite is not a yes to play
If you are the maybe
Give a time. "We will know by Thursday" is a maybe the host can use. "We'll see" with no day is a no they should treat as a no.
Both of you have to mean the yes. One partner's maybe is not a yes from the couple. Do not send a yes while the other person is still deciding.
If the day arrives and you are still unsure, say no. A late maybe is harder on the host than an early no. You can ask about a later night.
If you are the host
Count yeses. Do not count maybes. Set the list, the food, and the format for the people who actually said they are coming.
When you need the chair, tell the maybe the list is full for tonight. Offer nothing else in that message. A later night is a separate invite, sent when you mean it.
Do not tell the room that someone might still come. A surprise arrival is not a gift to people who planned around a number.
A maybe is not a yes to the format either
All mutual-yes matches are revealed, whether that happens together, at check-in, or after the short rounds. You should know which night you are considering before you turn a maybe into a yes.
A key party shows one Play Partner at the same time. A play party reveals matches at check-in. A speed date is short rounds, then yes or no. If you do not know which one the invite is, ask before you say yes. A yes to the wrong night is still a yes they planned around.
FAQ
Does a maybe hold my spot?
No. The host counts yeses. A maybe is a conversation, not a chair.
What if only one of us is sure?
That is still a maybe, or a no. Do not send a yes until both of you mean it.
When is a maybe too late?
When the host has already closed the list, or when the party is the same day. Say no, and ask about another night if you want one.
Should the host save a plate for a maybe?
No. Plan for yeses. A maybe who becomes a yes after the list is full hears that the list is full.
Is saying yes a promise to play?
No. A yes gets you on the list. It is not a yes to any person in the room. A maybe is not even the list.
Can I ask what the format is before I answer?
Yes. Ask whether it is a key party, a play party, or a speed date. Then say yes, no, or a time when you will know.