SOL (Scenario Overlay) is a special gameplay feature in Breath of Fire:Dragon Quarter. It encourages the player to return to previous points in the game, restart the game, and/or replay the game in order to unlock hidden areas and view additional story scenes.
When the player loses, obtains 100% on the D-Counter or uses an option called "Give Up" (to be used only when the game is deemed impossible to continue), the player is given two options -- SOL Restore and SOL Restart. SOL Restore allows the player to restart at the last save point with the characters at the same level in which they were defeated, while SOL Restart restarts the game entirely. Either option allows the player to retain any equipment equipped, any skills obtained, any Party XP earned, and any items and Zenny in storage. Additionally, after a playthrough, the player is automatically set to a SOL Restart.
In total, there are 25 SOL scenes to unlock.