Hi, first off huge congrats on getting to the AC! Really well done!
Generally what you can expect from negotiation exercises is:
1. Preparation time - You get split into teams and are given some information (the background to the exercise, what your clients want etc.) to read through and discuss with your other team members.
2. Negotiation - You then get taken into a different room where you and the opposing team start to negotiate and reach compromises based on what both your clients want.
Some tips:
1. During the preparation time, I always make a list of all the issues followed by what the client's ideal position/outcome vs least ideal outcome is on the issue. This then helps you work out with the rest of your team what you're starting point should be when negotiating with the other side and what the bare minimum you'd be willing to accept is (if forced to negotiate down). Starting with the best possible outcome (or perhaps even slightly more than the client wants) is also a good idea so that you ensure your client is getting a good deal even if you do have to concede some things.
2. Split the issues between each of your team mates so that each of you have the chance to take the lead on something during the negotiation and really showcase your skills
3. Do not assume that the other side has been given the exact same information as you. There's often quite a lot of conflicting information on both sides so ask a lot of questions for additional context and maybe don't give away your position on certain issues too quickly!
4. If you've been made an offer by the other side/been presented with new information, always ask for a few minutes to discuss it with your team. Sidebars like this are a great way to show teamwork but also give you a chance to gather your thoughts if things are getting tense.
5. Compromise! Good negotiations involve lots of compromise and not willing to change your position on anything is generally looked upon badly.
6. Timing - It's better to reach an agreement on all the issues rather than leave some of them undiscussed. So if you notice both sides being stuck for too long on one issue don't be afraid to intervene and mention the time and that it'd be best to decide on an outcome and move on.
There's also some more specific advice on the
Macfarlanes one here.
https://www.thecorporatelawacademy.com/forum/threads/macfarlanes-interview-2019-2020.2258/
Hope that helps!