A vital goal for most law-department retreats is to have the lawyers get to know each other better. Familiarity helps build trust and teamwork. One technique to help accomplish that goal, as well as to start the retreat off in an upbeat way, is to begin with an enjoyable ice-breaker.
One law department kicked off its conference by having each person tell two truths and a lie about themselves. From my experience at nearly thirty law-department conferences, I know that self-revelation embarrasses some people. That kind of ice breaker chills their hearts. A safer alternative is to have the leadership team give some personal history that the broader group may not know and the crowd has to guess which team member the fun fact applies to.
Another legal team used a jeopardy-style game that teaches the participants interesting things about the company. I can imagine a variation that turns facts about the law department and its history into jeopardy questions.
Dinners the night before the main conference begins are intended as icebreakers, but should you allow people to sit with whomever they want? Or do you use the dinners as a forced time to mingle?