Extra Little Sister Bug

In the PS3 "Greatist Hits" version of the game, in Neptune's Bounty, the "Upper Wharf" Little Sister (and her Rosie) will endlessly respawn. First, kill the Rosie and save the Little Sister (however you normally would). Then head back to the corridor (where the turret was/is, if you hacked it) between Jet Postal and Fighting McDonagh's Tavern. Once you reach the turret, turn around and head back to the original room, toward the passage up to the Wharfmaster's Office. A respawned Little Sister and her Rosie will appear on the left-hand side, a safe distance in front of you. Sometimes a splicer will appear, too, but this allows for great opportunities to take photographs and build photo points. Plus, each Rosie here leaves $78 after its death, which you can spend on 5-6 grenades in the nearby (hacked) vending machine. This makes for an easy and expedient way to build ADAM and photo points.

In the Neptune's Bounty and Fort Frolic levels of BioShock there are supposed to be three Little Sisters, and in Arcadia there are supposed to be two. However, in certain circumstances, players can be presented with another Little Sister after dealing with the others. When attempting to exit these levels, these players will be presented with a message informing them that they have not dealt with all the Little Sisters if (and even though) they dealt with the extra one.

Cause of the glitch
The extra Little Sisters bug is the result of scripted events that trigger a Little Sister and Big Daddy pair for a specific scene – typically a fight with Splicers. The triggers are usually as simple as entering a particular area (i.e. in Neptune's Bounty, it's the Upper Wharf; in Frolic it's the Atrium after visiting the Plaza the first time; in Arcadia, it's a Gatherer's Garden.) If the player avoids these trigger points until all Little Sisters have been dealt with, then entering the trigger area will spawn an extra Little Sister.

In other levels with these scripted events, it is impossible to avoid the trigger, because the player is required to pass through that particular area in order to advance the game. For example, in Hephaestus there is a Big Daddy defending a Little Sister at the entrance to the Core area the first time the player passes through, but since that is the only way into the facility, it is impossible to avoid triggering the event.

Neptune's Bounty
When the first Rosie is encountered in the dock area he should be walking towards the hallway. He will retrieve a Little Sister from the hallway before the dock. Kill the first Rosie and gather the ADAM from the Little Sister, but DO NOT walk across the muddy area to the other side of the dock because this might trigger the event. Rather than crossing to the other side, go through the door on this side of the dock.

Go to the Gatherer's Garden and open the menu. Do not go upstairs to the Upper Wharf. Instead, exit to the dock area opposite of the way entered. It may take a few repetitions of these actions to trigger the next Little Sister to spawn. Eventually, another Little Sister will spawn in the Lower Wharf where the first Big Daddy was killed. After dealing with her, head upstairs to the Upper Wharf for the third Little Sister. Normally, the one upstairs is the second Little Sister rather than the third, which leaves the fourth Little Sister for after the camera is retrieved. Just continue with the missions as normal and the remaining Little Sister should appear. After she is harvested or rescued, a fourth Little Sister symbol should appear on the pause menu.

Alternatively, simply don't talk to Peach Wilkins until three Little Sisters have been dealt with, and wait for new Big Daddies in each location to appear. After all three have appeared, talking to Peach will remove the gate, at which point the extra Little Sister can be seen. Save the game before fighting the Big Daddy, since if the player is killed, the extra Little Sister may have time to "go home" permanently.

Arcadia
There are normally two Little Sisters in Arcadia, but if players avoid the scripted fight between a splicer and Big Daddy at the Gatherer's Garden outside the Grotto area, then a third can be found. If the player hears a Big daddy fighting splicers when passing around this area before dealing with the two Little Sisters, it means that the event has already been triggered and it will be necessary to restart from a previous save to try again.

To trigger an extra Little Sister, go directly from the Tea Gardens to the Lower Concourse, avoiding the Gatherer's Garden in the upper area. Staying in the canal, travel all the way through to the Storage Room, then up the stairs to the Upper Rolling Hills where there should be a Big Daddy and a Little Sister.

After the first Big Daddy has been defeated and the Little Sister has been dealt with, trigger Andrew Ryan's radio message and release of the poison and go to Langford's lab, which will prompt the opening of the Tree Farm. Roam around the Upper/Lower Rolling Hills, the Tree Farm and the Storage Room until the second pair appears, but avoid the Gatherer's Garden. (NOTE: This Big Daddy and Little Sister are actually spawned or connected to the Storage Room, since the Little Sisters headed specifically to that vent in that area after they are rescued, even though she passed by closer vents.)

After the first two Little Sisters have been dealt with, head towards the Gatherer's Garden machine via the canal from the Tea Garden. The Gatherer's Garden must be approached as if the player were coming straight from the Tea Gardens to trigger the scripted event.

Fort Frolic
To find an extra Little Sister in Fort Frolic, do not return to the Atrium before three Little Sisters have been dealt with in Poseidon Plaza.

After gaining access to Poseidon Plaza, head to the plaza. Deal with all three Little Sisters within Poseidon Plaza, waiting for each Big Daddy to spawn after the last has been killed. When ready for the extra (fourth and last) Little Sister, head back to Sander Cohen's Masterpiece to find her, her spawning triggered by a fight between her Big Daddy and spider splicers.

Effect on Gifts and the Ending
The player receives gifts from Brigid Tenenbaum for every three Little Sisters that are rescued – seven gifts total and maximum – and extra Little Sisters count towards this number. Therefore, it is possible to get Tenenbaum's gifts early by saving the extra three Little Sisters. However, there is no extra eighth gift or message from Tenenbaum if 24 sisters have been rescued.

The ending cinematic the player receives after defeating Fontaine depends on the number of Little Sisters the player has saved or harvested. There are normally 21 Little Sisters in the entire game, but by successfully exploiting the glitch in each level there can be 24. Therefore, if the player has found extra Little Sisters, it is possible to harvest one without the game counting it toward the bad ending.