If you've been in a high-conflict divorce or custody case for more than two months, you've already discovered that some messages aren't really messages. They're traps. They look like a question about pickup logistics — but underneath they have three accusations, two emotional bids, and one phrase designed to make you reply in a way that looks bad in court.
BIFF was developed by Bill Eddy, a family-law attorney and licensed clinical social worker who founded the High Conflict Institute. It's the framework most family-law attorneys teach their clients. It's deceptively simple. It is not easy to do at 11:14 PM.
The four rules
Every reply you send to a hostile message should pass all four:
Brief
If your reply is over four sentences, you've lost. Long replies invite long counter-replies. They give the other side more material to work with. They expose more of you. The right length for a hostile-text reply is two to four short sentences. Sometimes one.
Informative
State only what's necessary — usually a fact, a confirmation, or a logistical answer. No interpretation, no defense, no explanation of why you're hurt. Information only.
Friendly
This is the rule that kills most people. Friendly does not mean warm or affectionate. It means civil. Use the other person's name. Use a neutral closing. The tone should be the tone you'd use with a stranger you don't dislike. The reason this matters: your reply is going to be read by someone who doesn't know either of you — a judge, a guardian ad litem, a custody evaluator. Friendly tells that stranger you're the reasonable one.
Firm
The reply should not invite further discussion of the inflammatory part. End the topic. Confirm logistics, decline the bait, move on. "Looking forward to seeing the kids Friday" is firm. "Why would you say that to me?" is the opposite.
Eight examples, before and after
Here's how this looks in practice. The "before" replies are real — names changed, edges sanded slightly. The "after" replies are what BIFF would generate.
1. The pickup-logistics ambush
2. The DARVO accusation
3. The 11 PM emotional bid
4. The financial pressure text
5. The schedule-change manipulation
6. The "what about you" pivot
7. The threat-shaped question
8. The kids-as-messenger trap
The three traps that kill BIFF
Trap 1: The defensive sentence you can't quite cut
You'll write the reply. It's three sentences. You're proud of it. Then you add one more sentence — "I just want to make sure we're on the same page about what actually happened" — and you've lost. That sentence is the foothold. Cut it. The other side does not need to be on the same page about what happened. They need to know what time pickup is.
Trap 2: Writing it for them, not for the judge
Most BIFF replies fail because the writer is still trying to make the other person understand. You will not make them understand. They are not the audience. The audience is the third stranger who reads this exchange someday — judge, GAL, evaluator. Write to that person. The hostile sender is just the address you're sending it to.
Trap 3: Sending it before the urge passes
You can write the perfect BIFF reply at 11:14 PM and ruin it by sending three more replies at 11:18, 11:24, and 11:31. Send the BIFF. Put the phone down. The follow-up texts you'd write in the next hour are exactly what the original message was fishing for. This is what the locked-draft cooldown in Compass is built for.
When BIFF is the wrong tool
BIFF assumes you have something to confirm — a logistical question, a schedule, a fact. If the incoming message is purely a personal attack with no logistical component, BIFF can come across as cold or evasive, and a judge reading the exchange might wonder why you didn't address what was said.
For pure-attack messages, the right reply is often no reply at all. Document the message. Don't engage. The absence of a reaction from you is itself the evidence. (For exchanges that escalate to safety concerns or threats, see Documentation that survives a hearing.)
The hard part
BIFF doesn't make the other person stop. That's not the point. BIFF makes your messages defensible, your tone consistent, and your record clean. Six months from now, when an attorney or a judge scrolls through the thread, your replies should look like the replies of the reasonable parent. Brief. Informative. Friendly. Firm.
And six months from now, you should also notice that the volume has dropped. Hostile messages need a reaction to feed on. BIFF starves them.
Related: Gray rock — and when it's actually the right call · Documentation that survives a hearing · The 11 PM rule