The Training Room is a type of room built inside the island base.
A Training Room is used to train your Minions to become more effective in their work. When the player has successfully captured a Hostage, the hostage can be interrogated to upgrade the one doing it into an advanced minion. Afterward, the advanced minion allows the player to quickly and safely train more by building and equipping a Training Room. Using the Minion Management screen, the player can increase the number of the advanced minion that was just upgraded by more. Minions will automatically upgrade using this room until the specified numbers have been met. Also, minions will use the room to replenish these numbers if some of the advanced minions die.
However, to use the Training Room, the player need the right furniture and at least one of the advanced minions that he wants to train more of to act as a teacher. If the player runs out of an advanced minion type, he will need to capture and interrogate another Hostage.