I posted this last night but got no feedback in another topic until I found there's a thread already here. So here you go guys:
Big fan here since ME1 who's hoping for more from ME3 endings. After much thinking, writing and re-writing, I came up with some ending ideas. The following are not only ending choices, but criteria for each ending and sequence of events and rationale behind each choice. I left out details about cutscenes, as they'll be in another write-up.
If Bioware is reading this, I hope they take into consideration of some of the stuff here.
Summary of the Endings:I have come up with distinct five endings with unique variations, summarized below:
1. Reverse Beacon: The Crucible and the Citadel become a Reverse Beacon, signaling the Reapers to return to dark space. This ending is the best in which all are saved.
2. Understanding: The Reapers understand how this cycle is unique, and therefore breaks the cycle. They retreat back to dark space. Like the first ending, all are saved.
3. EMP: The Crucible and the Citadel give out an EMP that destroys the Reapers. This ending has two variations, in which synthetics such as the Geth and EDI can be destroyed.
4. Control: To save themselves, the Reapers offer omnipotence to Shepherd, who fuses with them, becoming a god-like creature that controls the Reapers at his will.
5. Bleak: The Reapers destroy the fleets and damage the Crucible, and humanity and other races basically lose the war. This ending has two distinct variations, in which the relays are either inactivated or destroyed, with unique outcomes.
*I'll refer the endings as Reverse Beacon, Understanding, EMP, Control, and Bleak in the following sections.
Some characteristics of the endings:
In all five endings the Reaper threat is eliminated (except in a variation of Bleak ending). However, only in EMP and a variant Bleak endings are the Reapers actually destroyed. In all other endings the Reapers retreat to dark space or are under control by Shepherd. In addition, only in the Bleak endings are the relays destroyed or inactivated. As a result these all make the continuation of the Mass Effect universe possible.
Depending on Shepherd’s choice, a final boss of the Illusive Man in Reaper form is possible. To save themselves from destruction (EMP), banishment (Reverse Beacon), and control (Control), the Reapers reanimate the Illusive Man to fight Shepherd.
How are the endings fit to a particular player?A dutiful player, both paragon/renegade, may choose EMP to destroy the Reapers to fulfill his mission and end the Reapers’ reign. A more lenient, paragon player, may end the Reaper threat by forever banning them to dark space by using the Reverse Beacon. A renegade and ambitious player may choose the Control ending to end the war, but use the Reapers for his own bidding now. A hardcore paragon player may choose to forgive rather than vanquish his enemies by selecting the Understanding ending. And lastly, a player who fails to gather enough forces to defeat the Reaper is bound for defeat in the Bleak endings.
Summary of Ending Criteria:Mass Effect is a game of multitude of choices, and it would be difficult to factor in every decision into the endings. Please see the logic choice for these decisions in a later section. But here are the main criteria for ending choices:
1. War asset determines whether the Crucible is safe or heavily damaged. Having high effective military strength means that the fleets are able to protect the Crucible, and therefore the Reverse Beacon, Understanding, EMP, and Control endings are all possible. Having low effective military strength means that the fleets and the Crucible are heavily damaged. Therefore the only possible endings are the Bleak ones.
2. Reputation and paragon/renegade scales determine which ending or variation of the endings is chosen. For example, a player with low war asset has only bad endings to choose from. With default or renegade points, Shepherd destroys the relays and all lives within the supernova range. But with enough paragon points, Shepherd inactivates the relays.
3. Rannoch mission determines whether in the EMP ending the Geth and EDI are destroyed.
4. Other decisions in the series determine epilogue, cutscenes, and extra dialogues. For example, if Shepherd has romanced someone, extra dialogues and cutscenes appear.
Premises before the endings, about the Crucible and the ReaperWhat is the Crucible? How does it factor into these hypothetical endings?As the Prothean VI described, the Crucible is a mega-structure designed by aliens in countless cycles, with each cycle improving upon the last. Its purpose is to end the Reaper threat and break the cycles once and for all. In the hypothetical endings, the Crucible functions as a Reverse Beacon or EMP generator. However, the Beacon and EMP only travel at light speed because they are electromagnetic waves. In order for them to propagate further at FTL speeds across the entire galaxy, they need the Catalyst, which is the Citadel. Therefore for the Crucible to function, it attaches itself to the Citadel, and consequently the Citadel then propagates either the Reverse Beacon or EMP to distant relays. The Crucible is designed to attach only to the Citadel because the Citadel is the hub of all mass relays.
When the Crucible is damaged in the Bleak endings, it is unable to function properly to generate the Reverse Beacon or EMP. However, it can still produce enough power to overload the mass relays like a runaway, uncontrolled nuclear chain reaction. This can cause either inactivation (paragon Bleak ending), or destruction (renegade Bleak ending) of the relays.
Is the Crucible a control device allowing Shepherds to control the Reapers?In my hypothetical endings the Crucible is not a control/synthesis mechanism in the Control ending. As the Prothean VI states in Thessia, the Crucible was not completed in the last cycle because a splinter Prothean group who wanted to control the Reapers foiled its construction. Because of this reason, it would be illogical for the Crucible to be a control mechanism.
In the Control ending, the Crucible is merely a bargaining chip for Shepherd. Once the Reapers know that they have lost the war and are facing extinction by either the Reverse Beacon or EMP, they try to make a deal with Shepherd, making him omnipotent by giving him direct control over all Reapers. But Shepherd has to be fused with them in order for control to work.
How does the player (Shepherd) know what the Crucible does?When Shepherd activates the Crucible, a Prothean VI onboard the Crucible gives a history of the Crucible’s construction. The VI states how the Crucible functions as a Reverse Beacon or EMP (which are technologically possible given Protheans’ ability to construct their own Conduit in Mass Effect 1). The VI also gives rationale why the Citadel is the Catalyst needed to propagate the signal throughout the relay network. The VI also explains the function of the Crucible to Shepherd during dialogue.
What is the purpose of the Reapers?The Reapers destroy advanced organic races every 50,000 years to allow development of lesser life forms. But the Reapers’ ulterior motive is to prevent the organics from advancing enough to surpass themselves and from developing synthetics that would topple the Reapers. Therefore the Crucible signals their destruction, and in the Control ending they will try to make a deal with Shepherd to ensure their own survival. The Reapers represent the ultimate order, while the organics are the chaos of life and evolution. However, their origin, true intentions, and other characteristics remain obscure, and are beyond the understanding of the organics.
Who is the All-Reaper that Shepherd encounters in the end sequence/play?In these hypothetical endings Shepherd invariably reaches the final control center where he makes decides the fate of the galaxy. In here he meets the All-Reaper, which is equivalent to the Child AI in the released game. The All-Reaper is a virtual representation of the Reapers, and acts as their final voice. However, it is more of a hologram than an actual physical entity. Therefore it has no attack capabilities. Once the Crucible docks on the Citadel, the All-Reaper is powerless to overcome the Crucible. However, the All-Reaper retains certain power, and is able to “reanimate” the Illusive Man for the final confrontation in Reverse Beacon, EMP, and Control endings.
Details of the five endings:Reverse Beacon ending (high war asset, high paragon)1. The Citadel and the Crucible become a reverse beacon, signaling all Reapers to retreat back to deep space. Since the Reapers are not destroyed, now it is up to humanity and all other races in the galaxy to make sure that the beacon does not fall into the wrong hands. This is the “best” ending, a happy ever after ending in which Shepherd and everybody else survive.
Variations: 1.1: War asset and number of factions united decide how long the peace will last, and the epilogue states something about the peace.
1.2: Saving the Council and war asset determine who is in control of the beacon now. If the Council is not saved, humans now control the beacon. If the Council is saved, the Salarian, the Asari, and the Turians, along with humans, control the beacon. In addition, war asset determines which race suffers the most in the battle against the Reapers, and their resulting contribution in keeping the beacons are determined. All these can be done in text format in the epilogue.
Understanding ending (high war asset, very high paragon)2. Shepherd and the Reapers reach an understanding. The Reapers realize that this cycle is unique, in that instead of chaos of wars between synthetics and their creators, and among themselves, something grander emerges. And that is unity and peace. In this cycle, no single species reign and dominate over others, unlike the previous cycle in which the Protheans are the slave drivers of vast intergalactic empires. In addition, the risk of synthetics rebelling and destroying their creators is averted by the newly brokered peace between the Geth and Quarians, which has never happened before in the previous cycles. The Reapers therefore conclude that humanity and other races in this galaxy maybe deserve a chance to decide their fate for themselves. Now the Reapers retreat to dark space, but because they are not destroyed, they might come back if we resume walking on the path of evolution the Reapers imagined for us (i.e. self-destruction through wars or destruction by the synthetics).
EMP ending (medium to high war asset, neutral or renegade)3. The Citadel and the Crucible becomes an EMP shock generator, killing or inactivating all Reapers in the galaxy. This solves the Reaper problems once and for all, but with dire consequences for other synthetics (sees variation below):
Variations:3.1. Depending on Priority: Rannoch mission, the EMP can either spare synthetics, or destroy all synthetics including the Geth and EDI. If the Geth is destroyed in Rannoch, the EMP will also kill EDI. If the Quarians are destroyed, the EMP will kill the Geth and EDI too. However, if peace is brokered between the Geth and the Quarians, the EMP only kills the Reapers. The explanation for such EMP discrimination lies in the fact that if the organics and synthetics do not show their ability to escape from cycles of destroying each other (by making peace with each other), the EMP will to destroy all synthetics to save the organics. This ending is bittersweet in that all synthetics will die if the Geth and Quarians do not reach peace. These choices reward the players who completed the hardest yet the best outcome, in Priority: Rannoch.
Control ending (high war asset, renegade) 4. The Reapers face extinction from activation of the Crucible, and makes a deal with Shepherd, offering total control. There is always a potential for Shepherd to go rogue (he is going renegade now) and activate the Reapers for his own bidding. In this ending, Shepherd is fused with the Reapers, and becomes a god-like creature (like Paul Atreides from Dune) who can live for thousands of years. This is a renegade decision and the only ending with synthesis between organics and machines, and only to Shepherd. In the end Shepherd talks in a Sovereign-like voice and has blue robotic eyes. Shepherd orders all Reapers to stand down, and galactic peace is preserved at the moment. But who know what Shepherd will do in the future. This will be a mystery ending with cliffhanger, as Shepherd smiles mysterious in the epilogue.
Notes: This ending requires high war asset, therefore the Crucible is intact. However, the Crucible is not the means to control/synthesis (see premises section above). In summary, the Reapers are bidding to save their own existence, and offers Shepherd omnipotence in return. A renegade Shepherd might make this ending his top choice.
Bleak ending (low war asset, paragon/renegade/neutral) 5. The Reapers are all powerful, and because of low war asset (below minimum), the Reapers are stronger than the all the galactic fleets combined. As a result, the Reapers destroy the fleets and heavily damage Crucible, thereby preventing the Reverse Beacon, Understanding, EMP, and Control endings. The humanity is lost and the galaxy is doomed.
Variations: 5.1. The renegade option would have Shepherd activating a failsafe system on the Citadel, sending a signal to overload and destroy all mass relays in the galaxy. Because of this, all star systems containing mass relays are destroyed (through supernova formation), including Earth. Shepherd and everyone else die, along with all Reapers within the vicinity of the relays. However, the epilogue mentions that because the galaxy is vast and infinite, not all star systems have mass relays and consequently life and civilization can persist and grow in these “uncharted” worlds. In addition, because these civilizations do not have access to mass relays (and will never have the chance with the relays destroyed), they do not walk on the paths designed by the Reapers and therefore are free from them, as the Reapers need the relays to travel from one star to another. The epilogue finally states that the story in the galaxy does not end, but continues in a new path, free from the Reapers.
5.2. The paragon option would have Shepherd telling all remaining ships to engage FTL drive to reach Charon relay and prepare for a jump to their own home worlds in order to regroup and continue the fight. Shepherd is stranded on the Citadel because he is needed onsite to activate a failsafe system to send a signal to overload all mass relays in the galaxy, inactivating but not destroying them. After the ships make a suicidal breakout from Reaper encirclement to reach to Charon relay with heavy casualties, Shepherd activates the fail safe, sealing himself in Earth orbit. In addition, all Reapers are trapped in the star systems they are in, as are all the ships around Earth orbit. The ending has respective fleets coming out from their jump, arriving on their home worlds on fire. For example, we see Turian ships reaching Palaven, and Primarch or Garrus ordering his crew to make the last stand and fire their cannons. Meanwhile on Earth, Shepherd is looking at the Reaper fleets orbiting Earth, and his small contingent of Alliance soldiers cocking their rifles and looking at the distance. Shepherd and his romantic interest hold hands for the last time, and then Shepherd and his soldier charge. Then screen fades to black. This is an “open” ending (although bleak), and there will be no epilogue here.
Sequence of gameplay events leading to the ending:Summary of events: 1. London fighting: Shepherd fights the Reapers in the streets of London.
2. Dash for the beam: Shepherd and company runs to the beam.
3. Fighting on the Citadel: Shepherd is beamed up to the Citadel, where he continues the fight.
4. Encounter with the Illusive Man: Shepherd and Anderson confronts the Illusive Man.
5. Encounter with the All-Reaper and the Illusive Man: Shepherd and the All-Reaper exchange heated words. Depending on the condition of the Crucible, the Illusive Man may be reanimated in Reaper form to fight Shepherd (final boss fight).
6. Final Decision: Shepherd and the All-Reaper exchange more dialogues, and Shepherd makes his final decision sealing the fate of the galaxy.
7. Cutscenes and epilogue: Ending- and context-dependent cutscenes and epilogue.
Detail of events:1. London fighting: Shepherd and his squad mates fight on the streets of London. The Alliance and aliens races on the ground all make dash for the beam. However, they sustain heavy casualties, and only a few people manage to reach the beam and be transported.
a) This part is similar to the one in the released game.
2. Dash for the beam: Shepherd, his two squadmates, and Anderson are the main protagonists that manage to reach the beam under heavy fire. A few other soldiers also reach the beam
a) In here Alliance ships and land vehicles open fire on the Harbinger, distracting it and allowing Shepherd and his team to reach the beam.

Shepherd and company reach the beam with relatively minor damage, certainly not with charred armor and lost helmet. Therefore they can still fight on the Citadel.
3. Fighting on the Citadel: Shepherd and his squad fight against Citadel citizens turned into husks, as well as other Reaper creatures such as Marauders and others. During battle, the following sequence of events/choices open up:
a) One squad member needs to be left behind and hunker down to allow Shepherd and the rest to push forward. Shepherd has to decide whom to leave behind. War asset determines if this squad member survives or not.

After fighting a while, the other squad mate is critically wounded, and tells Shepherd to push on without him. Shepherd complies, and says his good byes. War asset also determine if this squad member survive or not.
Then Anderson and Shepherd both make final confrontation with the Illusive Man.
4. Encounter with the Illusive Man: Shepherd reaches the control room where the Illusive Man is waiting for him. The Illusive Man is indoctrinated and tries to persuade and force Shepherd into controlling the Reapers. Shepherd, Anderson, and the Illusive Man have a heated exchange (dialogue), and the following sequence of events/choices open up:
a) The Illusive Man tries to indoctrinate Shepherd into shooting Anderson:
i.
Paragon interrupt: Shepherd convinces the Illusive Man to shoot himself.
ii.
Renegade interrupt: Shepherd aims at the Illusive Man and shoots him.
iii.
Neutral: Shepherd shoots Anderson, mortally wounding him. Then Shepherd regains his composure and shoots the Illusive Man.

After confrontation against the Illusive Man, Shepherd activates a switch to open the wings of the Citadel. Admiral Hackett radios in that the Crucible is now docking.
c) At this point Admiral Hackett informs Shepherd about the condition of the Crucibledetermined by war asset.
i. High war asset: The Admiral says the Crucible is intact and is now docking.
ii. Low war asset: The Admiral says the Crucible is heavily damaged, but will try docking to see what happens.
5. Encounter with the All-Reaper and the Illusive Man (optional): After the Illusive Man is out of the picture, Shepherd encounters the All-Reaper (equivalent to Child AI). Shepherd and the All-Reaper exchange words), and discuss each of the available ending conversation. The following sequence of events/choices open up (see section on decision criteria for details):
a) Low war asset: The All-Reaper is omnipotent and basically says that Shepherd has failed and humanity and the others have lost the war, time for extinction. In this case the game directly progress to the next stage, final decision.

High war asset: The Crucible is intact and docks with the Citadel. To prevent Shepherd from activating the Crucible, the All-Reaper reanimates the Illusive Man in Reaper form to fight Shepherd.
c) Shepherd needs to defeat the Illusive Man, failure to do so take to game over screen.
6. Final decision: After the battle against the Illusive Man, Shepherd and the All-Reaper exchange more words. He finally makes his final decision, and cutscenes and epilogue ensue. See previous sections on the specifics.
7. Cutscenes and epilogue: Ending- and context-specific cutscenes ensue. Provides closure for all the important decisions in the game (see section on notes).
Decision criteria and logic: How are decisions made? By both prior decisions and ongoing decisions.Ending choices in Mass Effect games are decided by prior decisions (before end mission) and ongoing decisions (during end mission). For example, in Mass Effect 1, ending decisions mainly revolve around whether the Council is saved or not. In Mass Effect 2, ending variations revolve how many crew members survive. In Mass Effect 1, whether the Council is saved is determined on the fly as Shepherd fights in the Citadel. In Mass Effect 2, number of surviving crew is decided by prior choices such as loyalty missions, and ongoing choices such as who to go into the vents and who to lead the stranded crew back to Normandy.
Similarly, choices in these hypothetical Mass Effect 3 endings are also dependent on both prior and ongoing decisions. Prior decisions include war asset, paragon/renegade scale, and Priority: Rannoch. Ongoing decisions include dialogue with the All-Reaper and many others, which are essentially player’s own choice.
The endings and their criteria:1. War asset determines whether the Crucible is safe or heavily damaged by Reaper fire. Consequently, having high war asset means Reverse Beacon, Understanding, EMP, and Control endings are possible. Having low war asset defaults the player to only Bleak endings.
2. Paragon/Renegade scale determines the outcome of the endings. For example, high war asset allow for four endings (see above), but paragon/renegade scale allows for unique dialogue choices, which lead to one of the four endings. Both type of reputation (paragon/renegade) and scale of reputation (high or low) are taken into account. Neutral here means reputation scale below required for paragon/renegade choices.
Logic tree for endings:Low war asset → high paragon → unlocks Bleak ending (variation paragon)
Low war asset → neutral or high renegade → unlocks Bleak ending (variation renegade)
*in Bleak endings, no final battle with the Illusive Man takes place.
High war asset → high paragon → unlocks both Reverse Beacon and Understanding endings
High war asset → neutral → unlocks only EMP ending
High war asset → high renegade → unlocks Control endings
*in these endings, final battle with the Illusive Man takes place.
Note this decision tree is additive, not exclusive. For example, a player with low war asset but with high enough paragon and renegade reputation is able to unlock both versions of the Bleak ending. Similarly, for a player with high war asset, a high paragon by definition also unlocks EMP ending in addition to Reverse Beacon and Understanding endings.
Last but not least, war asset determines if squad mates Shepherd brought to the Citadel survive.
Some common questions1. Why does the All-Reaper offer Shepherd control in the Control ending?If the Crucible is intact because of protection from high war asset, then by default the EMP ending is possible. Now, because the All-Reaper cannot stop the Crucible from firing, it needs to bargain with Shepherd for the Reapers’ survival. In turn, the Reapers offer Shepherd omnipotence, longevity, and control over the most powerful entities in the universe- themselves. Theoretically by controlling the Reapers, a renegade Shepherd can end the war.
2. Why does the All-Reaper reanimate the Illusive Man? Doesn’t he also want control?In EMP and Reverse Beacon endings, the All-Reaper reanimates the Illusive Man to fight Shepherd, trying to prevent him from activating the EMP or Reverse Beacon to destroy the Reapers. Although the Illusive Man wants and is capable of controlling the Reapers to a certain degree, he is essentially indoctrinated, and therefore only a puppet to the All-Reaper. Therefore if the Reaper had to choose by whom to be controlled, the Illusive Man is an obvious choice, much better than the strong-willed Shepherd. As a result, even in the Control ending, the Reapers will reanimate the Illusive Man to defeat Shepherd.
3. Does Shepherd know the EMP will destroy synthetics other than the Reapers as well?It is possible to unlock both EMP and Reverse Beacon if the player has both high war asset and paragon reputation. The Prothean VI onboard the Crucible will tell Shepherd what are the functions and their advantages and disadvantages. The VI would state that the Reverse Beacon will end the war now and send all Reapers back to dark space. But they may find a way to come back, however slim their chances are. The EMP, on the other hand, will destroy all Reapers and necessarily prevent their return. However, the VI mentions that the effect of the EMP on the Geth is unknown, because the Geth is a synthetic race and even more so, it now has the Reaper code (from Priority: Rannoch). Therefore it will be a gamble for Shepherd to activate the EMP. However, the EMP ending is designed to reward players who have gone their way to broker the peace between the Geth and the Quarians, thus:
a. If peace if brokered in Priority: Rannoch, the EMP spares all synthetics.
b. Otherwise, the EMP will wipe out all synthetics, including the Geth and EDI.
4. What happens to the Crucible if Shepherd chooses the Understanding ending?Understanding ending is unlocked for a player with high war asset and very high paragon reputation. This ending is for the hardcore paragon player who is able to forgive rather than vanquish his enemy. In this ending, the Reapers realize that this generation is the one that breaks all cycles, and they acknowledge such feat and agree to return to dark space on their own. The Crucible is safe for humanity and other species’ keeping, and acts as a safeguard in the future if the Reapers do invade again.
:happy: