How to Unlock Practice Battle in The DioField Chronicle
What is Practice Battle?
Practice Battle is an unlockable feature in The DioField Chronicle‘s main story campaign which allows you to replay completed missions. Doing so lets you farm money and Ability Points (AP) which is useful for building your team to take on tougher missions later in the game. Being able to redo missions is also useful for acquiring bonus rewards, particularly Skill Points (SP), that you missed on your first run.
Clear Coswell Volcano Expedition (Chapter 1) to Unlock
To unlock Practice Battle, simply clear the Coswell Volcano Expedition mission in Chapter 1. Afterwards, Practice Battle will become available near The Institute (research facility on the first floor) which will allow you to replay missions as many times as you want during the main story campaign.
Benefits of Grinding Missions
Farm Ability Points (AP).
You can grind missions indefinitely to level up and gain AP. For an easier time, try to run a mission that you can clear fast and without much effort to micromanage units.
Farm money (Guld).
You can also farm money by constantly replaying missions. This is especially important during the early stages of the game as weapons, accessories, and items from the shop are quite expensive.
Acquire missed bonus rewards.
It is likely that you will not be able to get all bonus rewards on your first run of each story mission in the game. Do Practice Battles to get another chance of claiming them. Note that these bonus objective rewards are one-time only so it is impossible to farm them once you have obtained them the first time.