Lives are the main resource in the game. They are required to play levels. Each life gives you one try at completing a level. If you pass the level, you retain the life, but if you lose, then one life is deducted.
The maximum number of restorable lives is 5. However, this limit can be increased if you have an active Gold Pass for a season event (up to 10 lives).
Lives restore automatically over time, and you can see a timer showing the time remaining in the top right-hand corner of the game, where the number of lives you have is displayed. Extra lives can be obtained from your friends on Facebook who also play Clockmaker, or from other players in societies created directly in the game itself.