As in previous games of the franchise, in The Sims 3 players control their own Sims' activities and relationships. The gameplay is open-ended and does not have a defined goal. The sims live in neighbourhoods, now being officially referred to as 'worlds', which can be customized, allowing the player to create their houses, community lots, and sims, although many of these come with the core game. These worlds are now 'seamless', allowing all sims to move around freely without any loading screen in between lots, as happened in the previous games. Thus, the neighbourhood includes community lots which can be leisure lots (such as parks, gyms, and movie theatres) and job lots (town hall, hospital, businesses). Since the neighbourhood is open, the game includes the "Story Progression" mechanic, which allows all Sims in the neighborhood to autonomously continue their lives without the player ever controlling them. This helps to advance the story of the whole neighbourhood instead of only the active playing units. Sims live for a set duration of time that is adjustable by the player and advances through several life stages (baby, toddler, child, teen, young adult, adult, and elder). Sims can die of old ageor they can die prematurely from causes such as fire, starvation, drowning, and electrocution.