The Mass Effect trilogy is all about choices in that decisions can impact Commander Shepard's stories down the line, including between games. Players can transfer their save file between games, meaning previous choices such as the fate of certain characters or how certain missions were handled may be referenced in Mass Effect 2 and 3. This post contains spoilers for Mass Effect 2 and 3. 

But in Mass Effect 3, this is especially true because of the war assets leading up to the final battle against the Reapers. How exactly it goes down, and who survives, is determined by a number of factors much like the suicide mission at the end of Mass Effect 2. While Mass Effect 2 influences 3 heavily, a few factors from Mass Effect 1 roll over as well, including who of either Kaidan or Ashley survived on Virmire, if Shepard talked down Wrex, and sparing or killing the Rachni Queen on Noveria. Here's which decisions carry over to Mass Effect 3 and impact Shepard's final mission.

RELATED: All Mass Effect 1 Choices That Carry Over To Mass Effect 2

The outcome of the suicide mission is one of the most influential factors going into Mass Effect 3. Any squad member can die during the suicide mission, so it's important to prepare for it. If Garrus or Tali die, their roles will be filled by other characters. Whether or not the crew survives Mass Effect 2 also determines whether or not they appear in the second game. Kelly Chambers will only reappear if Shepard had dinner with her. And selling Legion to Cerberus during the final mission will make him an enemy in the third game.

Shepard must choose to save either Samara or Morinth during Samara's loyalty mission. Whoever they saved with show up in Mass Effect 3; Samara will help Shepard during a mission but Morinth will simply send an email. And during Mordin's loyalty mission, Shepard must decide whether to destroy the genophage research data or to keep it, which has consequences for the Krogan named Eve.

Several characters can be romanced in Mass Effect 2. Any romances from Mass Effect 1 — Liara, Kaidan, and Ashley — can be preserved for the third game. Unlike Kaidan and Ashley, players can reaffirm their romantic relationship with Liara during Lair of the Shadow Broker, but if Shepard chose to romance someone else after starting a relationship with her, she will mention this during Mass Effect 3. Anyone who was a squadmate in Mass Effect 2 can only be romanced in 3 if continuing that relationship from the second game. This includes Jack, Miranda, Tali, Thane, and Garrus.

Finally, destroying the Collector Base during the suicide mission will award Shepard with the Reaper Heart war asset, while preserving it will award the Commander with the Reaper Brain war asset.

RELATED: Mass Effect 3: What Happens if Garrus Dies in ME 2?

Smaller decision in Mass Effect 2 that will be referenced during Mass Effect 3 or influence the course of the game includes choosing whether or not to be reinstated as a Spectre, punching the journalist Khalisah al-Jilani at the Citadel, and completing the DLCs Overlord, Lair of the Shadow Broker, Firewalker, and Arrival. Completing those DLC packs adds unique dialogue but will otherwise not have any impact on Shepard's war assets as completing the DLC was not required in the original trilogy.

During another DLC that introduces the thief squadmates Kasumi, Shepard will decide whether or not she keeps or destroys Keiji Okuda's graybox. During Tali's loyalty mission, there's a chance she will become exiled. If this happens, peace between the Quarians and the Geth will be more difficult to achieve. This task will also be impossible if Legion or Tali die during Mass Effect 2's suicide mission.

Mass Effect: Legendary Edition is out now for PC, PS4, and Xbox One.

MORE: Should Mass Effect 3 Choices Carry Over to the New Game?