Glossary
White cell
The exercise-control team that plays every party not in the room, such as the attacker, regulator, media or vendor, and manages the flow of injects.
The white cell (also called the simulation cell or exercise control) is the group of exercise staff who control the scenario and role-play all the people and organisations that are not represented by players.
When a player says "we would call our cyber insurer" or "we'd ask the bank to recall the payment", the white cell answers in character. It can play the attacker in a negotiation portal, a journalist, a regulator, a managed service provider, a cloud provider's support desk or a key customer. This keeps the scenario realistic and tests whether players know what information third parties will ask for.
The white cell also manages timing: delivering injects from the MSEL, adding contingent injects when players take unexpected paths, and advising the facilitator when to skip or compress.
In a small tabletop, the facilitator and one controller may form the entire white cell. Each simulated party should have a short script describing what it knows, what it wants and what it will refuse. See tabletop exercise roles.