sham battle; mock battle; war game
A simulated combat exercise used in military training, gaming, or competitive contexts. Can also refer to a dry run or practice scenario.
The Self-Defense Forces plan to conduct a large-scale mock battle next month.
At the gaming tournament, a mock battle between pro teams was shown to the public.
Compound of 模擬 (mogi, 'simulation') and 戦 (sen, 'battle'). The word is a straightforward modern formation.