Plot
Arriving on Foundation Prime, a shapeshifting planet located in the center of the Lego multiverse, Lord Vortech, a being who has the power to shapeshift and travel through dimensions, and his robotic servant X-PO seek the twelve Foundation Elements, the cornerstones of time and space itself, in a bid to merge all the dimensions into one under Vortech's control. These elements, such as the ruby slippers, the One Ring, the flux capacitor, the Palantír, the P.K.E. meter and Kryptonite, were scattered across the multiverse long ago, but gathered together at Foundation Prime's palace can release the Foundation of All Dimensions, a force that bestows upon the user total control over the multiverse. When X-PO voices his doubts about Vortech's plot, Vortech decides that he no longer needs him and banishes him to the dimensional void Vorton, disregarding the risk in harnessing the elements. However, Vortech's body cannot handle too many more dimensional jumps, forcing him to open rifts to the multiverse's dimensions and recruits their villains to his cause while taking its heroes pulled through them hostage. These actions damage the boundaries between the multiverse, causing some of its aspects and inhabitants to be displaced.
When Robin, Frodo Baggins and MetalBeard are abducted, each unknowingly in possession of three of the elements, Batman, Gandalf the Grey and Wyldstyle are quick to be in pursuit. The trio get pulled into Vorton, where the rift generator they came out of explodes, prompting them to rebuild it. Aided by X-PO, the heroes use the generator to travel through the dimensions and search for the Foundation Elements and the five missing Keystones that power the generator (Shift, Chroma, Elemental Phase, Scale and Locate), hoping to find their missing friends and foil Vortech's plot. Along their journey, aided by "Keystone Devices" that allow them to use the Keystones' power, they meet and assist the various heroes of the dimensions they visit such as Dorothy Gale, Homer Simpson, Emmett Brown, Wheatley and Mystery Inc.. However, they are also pitted against numerous villains like the Wicked Witch of the West, Lord Business, the Joker, Master Chen, Saruman the White, Lex Luthor, the Daleks and Cybermen, Two-Face, Sauron, the Overlord, Brainiac, the Riddler, General Zod, as well as a pair of confrontations with Vortech himself, who eventually learns about X-PO's involvement. The heroes travel to Foundation Prime to rescue their friends and oppose Vortech, but it turns out to be a diversion that allows his minions to infiltrate Vorton in their absence and retrieve the rest of the Foundation Elements they had collected. With all of the elements gathered, the Foundation of All Dimensions, a green Lego baseplate, is released and Vortech is imbued with near-unlimited power. He then merges the heroes' friends and a piece of himself into a giant mutant known as the Tri and sends it to wreak havoc on the trio's origin dimensions. Fearing that another failure could lead to a transformation into a similar mutant, Vortech's henchmen leave.
The heroes free their friends from the Tri and destroy the Vortech piece, causing it to implode. Afterwards, Batman realizes that they will need all the help they can get to defeat Vortech, leading them to recruit The Doctor, Mystery Inc., the Ghostbusters, the spaceship Defender and GLaDOS to their cause. While the Doctor, GLaDOS and X-PO work on a plan to defeat Vortech via imprisonment within an endless rift, inspired by a time when he attempted to dispose of the heroes earlier, they head to Foundation Prime, fighting him along the way. With their allies' help, they are able to neutralize the Foundation, which causes Foundation Prime's palace to collapse, infuriating Vortech. He has one last confrontation with the trio, but the Doctor is able to manipulate the rift technology and sucks all of them into the endless rift. Using special devices he, GLaDOS and X-PO designed, the heroes are able to permanently imprison Vortech in the rift, saving the multiverse.
In a post-credits scene, an unknown figure finds a piece of Vortech, the same one that had survived the Tri's vanquishment, in the remains of Foundation Prime's palace. He picks it up and becomes corrupted, yelling in pain as it transfigures him. Vortech's laughter is then heard, implying that the figure has become a doppelgänger of him.
Additional levels typically retell plots such as that of Back to the Future, Ghostbusters, an episode of The Simpsons and more. However, there are also some original storylines, which often tie back to the original Lego Dimensions story in some way. The Portal Level Pack features Chell and Wheatley being returned to Aperture Science following the events of Portal 2 and ultimately finding another rift generator that GLaDOS had recreated. In the Midway Games Level Pack, a character known as the Gamer Kid discovers that the doppelgänger of Vortech has tampered with an abandoned amusement arcade's games, causing their protagonists to enter the real world. The Sonic the Hedgehog Level Pack follows Sonic as he searches for his friends and the Chaos Emeralds, all scattered across their origin dimension after an incident involving a Keystone Device that Doctor Eggman attempts to use for his latest scheme. The Doctor Who Level Pack is disconnected from the original story and focuses on the Doctor as he attempts to foil the Daleks' plot of converting Earth's population into more of their kind.
