So a pretty huge glitch was discovered in LEGO Dimensions.
DarkspinesSonic (Sonic fans might know him) found an easily executed glitch that allows you to use the game's "Hire-A-Hero" feature, but keep the hired hero beyond the 30-60 second time limit you normally have to use them, essentially allowing you to play as some characters without actually owning them. He also discovered a way to clone heroes you already own.
But I did some playing around with the glitch myself and discovered a lot of weird nuances to it. But the big, most exciting thing I found, was that you can actually take these glitched Hired Heroes back to the Vorton hub. Now, normally, to get into an Adventure World from the Vorton hub, you have to have a character from the corresponding franchise on your toy pad every time you want to enter (this means you can't simply borrow a friend's figure, enter the world, and then have it unlocked permanently. You need the toy there every time). However, using this glitch, you can trick the game into thinking you have a character on the toy pad when you actually don't, allowing you to gain access to Adventure Worlds you normally would have to buy a pack for.
In the case of Year 2 content, you need to also download that content before you execute the glitch, from the game's options menu. In the example in my video below, I used Finn to get into the Adventure Time World, even though I don't own him. I had to download the Adventure Time Level Pack content beforehand though, as the Adventure World's data is in that.
Unfortunately, to access Story Mode levels from Level Packs, you still need to genuinely buy the characters, as it seems the physical act of scanning a character in unlocks the levels tied to them. Whereas with Adventure Worlds, the game merely checks for characters in your in-game party (which would normally just so happen to be the characters you have on the toy pad). However, I need to check with Story Pack levels. I heard those are actually accessed through the corresponding Adventure World, so it may still be possible to enter those levels if that's the case.