The MCU's Incursions Explained Before Avengers: Doomsday

Incursions have become integral to the Marvel Cinematic Universe. And while some MCU directors find them stressful, they'll be hugely important to "Avengers: Doomsday," so watch Looper's video above to get the full breakdown.

Incursions were introduced during the "Secret Wars" comic event. They were kickstarted by a race known as Beyonders to wipe out the multiverse. With no Beyonders in the MCU, they've received a bit of a facelift. As explained in "Doctor Strange in the Multiverse of Madness," incursions occur when the barrier between different realities deteriorates, causing two worlds to collide with one another. This deterioration can occur as a result of dreamwalking (where a person possesses a multiversal counterpart), prolonged multiversal travel, or a misplaced individual being in the wrong reality. 

In that film, Doctor Strange (Benedict Cumberbatch) of Earth-838 destroyed a reality via incursion by dreamwalking to figure out how to defeat Thanos (Josh Brolin). The ending of "Multiverse of Madness" sees Clea (Charlize Theron) recruit the Sacred Timeline's Doctor Strange to help her stop an incursion he's caused with his own multiverse meddling. 

Kang the Conquerer (Jonathan Majors) brings up incursions in "Ant-Man and the Wasp: Quantumania" in reference to a multiversal war amongst various Kangs. However, those incursions were brought under control by He Who Remains. While we've seen the impact of incursions before, "Avengers: Doomsday" looks to take the concept to the next level.

There's still much in "Avengers: Doomsday" shrouded in mystery, since it doesn't come out in theaters until December 18. But thanks to the extra scenes presented in "Avengers: Endgame Encore," we know incursions will be there in some capacity. One of the post-credits scenes for "Avengers: Endgame Encore" sees the Time Variance Authority introduced in "Loki" reacting to thousands of worlds colliding with one another and getting destroyed. 

Something has clearly happened within the multiverse to trigger all these incursions simultaneously, and it likely all comes down to Steve Rogers (Chris Evans) messing with the timeline. At the end of "Avengers: Endgame," Steve puts the Infinity Stones back where they belong but then stays in the past to be with Peggy (Hayley Atwell). Another "Encore" post-credits scene shows Steve dancing with Peggy until he's paid a visit by Loki (Tom Hiddleston).

More than likely, the explanation will be that Steve staying in the past, thereby creating another timeline, fractured the multiverse. A misplaced individual is one of the causes of incursions. Combined with all of the other multiversal shenanigans we've seen in the MCU so far, it's possible that everything is now breaking all at once. And now, Doctor Doom (Robert Downey Jr.) is gathering heroes to set reality right in a way he sees fit. If you're still a little iffy on what incursions entail, watch Looper's video above that goes into more detail.