A Soul Knock is BiggDate's mechanism for starting contact. To open a conversation with a match, you compose a question for them. They see your question and answer it. They then ask you a reciprocal question. Only after both sides have answered does the chat thread open.
The purpose of a Soul Knock is to filter out 0.5-second appearance-based decisions. On most dating apps, a swipe is a coin flip on a photo, and 'match' means almost nothing. On BiggDate, a successful Soul Knock means two people demonstrated effort and curiosity about each other before any chat began.
Soul Knocks have a small daily allowance so each one is deliberate; they do not replace messaging. After both have answered, chat works like any messaging app — but the friction is concentrated at the front of the relationship, not the back.
Compare to: Hinge's 'like a prompt + comment' mechanic, which is closer in spirit but keeps photos as the first impression. Compare to: Bumble's women-message-first model (now being relaxed through Opening Moves), which addresses low-effort openers but not the photo-first problem.