Like many other characters in Mass Effect 2, Tali can die during the final suicide mission. Here's what will happen to Tali's character if she doesn't make it to Mass Effect 3.
This guide contains story spoilers for Mass Effect 2 and 3.
Tali'Zorah nar Rayya appears in all three Mass Effect games, later becoming a romantic option for a male Commander Shepard. Tali is a Quarian scientist, and she takes a special interest in Shepard's ship, the Normandy. Throughout the trilogy, she can provide some important intel and ideas regarding the Normandy, but her defenses in battle are quite low, so Shepard needs to take extra care when deciding where to assign her during Mass Effect 2's suicide mission, which comes in the third act of the game. Tali can die if Shepard fails to complete her loyalty mission and by assigning her to a position that requires high defenses or with a wrongful squad combination.
Tali plays a much larger role in Mass Effect 3 than she does in either of the other games. Despite this, if she dies in Mass Effect 2, she simply won't appear in the next game, and her role will be filled by another character the same way that Liara T'Soni succeeds some of Garrus' responsibilities if he dies during the suicide mission.
There's a story arc regarding Tali, her father, and research on the Geth that calls back to her loyalty mission in Mass Effect 2, Tali: Treason. In Mass Effect 3, Tali would serve as the Geth software expert when they infiltrate the Geth Dreadnought. This is another pivotal moment in Tali's storyline where she can die if the mission doesn't go according to plan or if Shepard makes the wrong choice. However, if dies during the suicide mission in Mass Effect 2, her role will be filled by Admiral Daro'Xen vas Moreh and Shala'Raan.
This also means that there's no opportunity to negotiate peace between the Geth and the Quarians. Having Legion alive is also essential in brokering peace between the two races. Having either of them missing means Shepard must make a decision between saving only one of the two species.
If Tali didn't survive the suicide mission in Mass Effect 2, this also means that, rather than a cutscene of her showing during Priority: Earth, a Geth Prime will appear in her place, but only if the Geth were spared in a failed attempt to negotiate peace.
If players want the best chance at keeping Tali alive for Mass Effect 3, it's important to keep her loyalty, specifically by not siding against her during the argument between her and Legion.
Mass Effect: Legendary Edition is out now for PC, PS4, and Xbox One.
