These are often military simulations conducted in open areas instead of training facilities or military academies, such as training fields, bombing ranges, and even closed-off, typically publicly-accessible areas.
Field training exercises rarely reach division strength.
Nearly every possibility is considered during planning, and often the scenarios can be more difficult or more far-fetched than actual battles, thus sharpening the skills of those participating to a level which will surpass that of the enemy.
The purpose of this is to give soon-to-be soldiers a taste of battle before they leave basic training, and can act as a medium to perform summative and formative assessments.
This also allows instructors to look for mistakes and correct them before their recruits graduate their course and potentially go to battle.