Defence Drill is a simulation mode unlocked after completing Chapter 2-4 Night. It costs 5 Sim Energy to start up, and up to 4 Echelons can be deployed. In it, your echelons will, 1 at a time, face off against a wave of enemy units in direct battle, progressing through floors in order. Each floor contains one wave, and you can choose which of your echelons will face it. Every 10 floors, you will face a somewhat more powerful enemy force (usually including a boss). Completing this floor saves your progress and gives you a reward package. Like all simulations, your units have unlimited ammunition and rations, so you don't need to worry about that. However, damage done to your units is retained between waves, so you may be forced to stop due to attrition. Obviously, like all sim battles, this damage is removed once you leave and come back.

The primary reason for doing this is of course, precious calibration tickets, which are used primarily for... calibrating your equipment. And also changing fairy talents, but that is expensive and will be detailed more on the fairy relevant pages. Due to the sheer cost of entering Defence Drills, these tickets are thus all the more valuable. If you want to complete your "complete 4 sim battles" dailies with these, you generally do 2 defence drills for 5AP each, and 2 of a random 1AP sim for 4 battles within 12 AP.

Note that you can face both day AND night battle conditions in defence drill, but because you don't need to navigate and merely fight directly, handguns are NOT necessary during the night sections.

A complete list of enemies from Defence Drill.

Reward List#

These are the bonus rewards you get for reaching certain checkpoints. For whatever reason EN doesnt actually tell you what they are, but here they are. Rewards are cumulative so if you reach multiple in 1 go, you get all of them. All you need to do is clear the floor you get it automatically. It's not mailed or anything, its just "surprise, you have stuff in your resource pile now"

3 resources obviously refers to manpower/ammo/rations. You may notice a pattern here.

...Nah.