Games that would like to facilitate this lens must ensure that the player is able to move about the environment without any artificial barriers there to hinder them. The player must not be constrained to do anything and is allowed to perform actions within the realms of the game according to his own free will.
Sandboxes are physical manifestations of the concept of autonomy. It allows the children to build whatever they want to only restricted by their imaginations.
In Far Cry 3 the player plays as the protagonist, Jason. Jason and his friends get stranded on a pirate infested island. The player has to play through the game saving his friends. The game is mission oriented, but to start a mission you need to go and stand on the mission marker to trigger it. Hence if the player doesn't trigger the mission, the player has freedom to move around the island. It is a very scenic island and exploration gets the player accustomed to the environment, which may prove to be an asset as the game progresses. Additionally the player also discovers various small tertiary mission due to the sand box nature of the game.
A true sandbox allows the environment to be altered by the player's actions. This change should not disrupt the actual storyline of the game. The game should make considerations for the actions done while the player isn't on a mission. This feature may be restricted if it proves to be more of a hindrance than an asset.
If your game doesn't have anything visually spectacular that the player may want to take time to see, a sandbox may actually have negative effects. It would mean the player is wasting time between missions, not accomplishing anything. So to use this lens, make sure that the environment the player plays in is luring and invokes the players sense for exploration.
Motivations :- Autonomy, Curiosity
Components :- Exploration