When I work with couples, I always, playfully, introduce the ground rules with reference to the film Fight Club. For those who have not seen it, there are two rules that are essentially the same: “You do not talk about Fight Club.”

In couple therapy, this translates into two critical safety mechanisms.

The first is that what is said in the session stays in the session. Unless both partners can agree that a session will not be followed by a fight about what was said, no accusations, no interrogations, no post-session cross-examinations, the work will not move forward. This is a non-negotiable boundary. As the work progresses, difficult things will be said and heard, often things that have never been spoken before. The rule is protective. It stays here.

This does more than contain the session. It creates a space in which different kinds of conversations can happen without fear of retaliation or anxiety about how they will play out later. It allows the interaction to be held long enough for something different to occur. It also prevents what is said in the session from being folded back into the existing pattern and used as material for the next argument.

This connects directly to the second rule.

The second ground rule is to actively refrain from having conversations about the relationship at home. This almost always creates resistance, particularly from the partner who typically initiates those conversations. It is critical.

These conversations are usually the most compromised space in distressed relationships. They merge quickly into arguments, or the relationship becomes saturated with talking about itself. In other cases, they are avoided altogether until they erupt under pressure. A central issue here is the imbalance of definitional privilege, who gets to define what is happening, what it means, and what needs to change. This is rarely equal.

What should lead to repair instead contributes to injury and maintains the pattern. Couples do need these conversations, but before that, their capacity to have them constructively has to be built.

Over the course of the work, this capacity is developed in a structured and contained way. Couples learn to engage differently. But at the beginning of therapy, these interactions are so destabilised that they do the opposite of what is intended. For this reason, they are removed from the couple’s day-to-day interaction until something different has been established.

Depending on the pattern, this rule is usually harder for one person than the other. This is common in approach-withdraw dynamics, where one partner has been actively trying to have more of these conversations, while the other experiences the rule as relief. That tension is expected, and it is addressed directly when the rule is introduced.

The rule also releases both partners from continuing to try to fix the relationship in the same way. It shifts the focus away from managing the relationship directly and back onto what each person is doing within the interaction. In the early stages of therapy, the therapist fulfils that function. Only later is it returned to the couple.

The Fight Club rules are one of the oldest components of how I work. When they are not followed, intensity escalates beyond what is workable. Later in therapy, this changes. The aim is for the couple to be able to reintroduce these conversations differently, to interrupt escalation, and to engage in repair in a way that does not recreate the pattern.