In order for you to play A Total War Saga: THRONES OF BRITANNIA on macOS with minimal graphics settings, your computer must meet the following requirements
Operating System:
macOS 10.13.4
Processor (CPU):
1.8GHz Intel Core i3 or better
Memory (RAM):
8 GB RAM
Graphics Card:
1GB Nvidia 650M, 2GB AMD Radeon M290, Intel Iris Pro 5200 or better (see notes for more details)
Storage:
15 GB available space