Welcome to the Tournament ArenaBlood Wars tournaments are cellular competitions between white blood cells. Two people’s cells fight each other. These tournaments playfully push the idea of combating opponents, and pose questions about the body’s ‘defense’ system – or rather how we think about our ‘immune’ system. The games play in the moment and highlight the immediate struggles of the cells: did the donor get enough sleep that night? Did they have a stressful day? The tournaments are play-offs, geared to find the strongest person. But what defines ‘strength’ or success in this case? These tournaments raise more questions than they resolve.