Specially added for Carnegie Mellon’s A Midsummer Night’s Dream, because, to be fair, Euripides’ Theseus has very little to do with Shakespeare’s Theseus. [The origins are different, Shakespeare's Theseus is mostly likely Chaucer's, not an actual Greek author. Maybe Plutarch's. Maybe.]
So Theseus had sooo many adventures. Here are a selected few that give you the more heroic, tricksy side of him.
One of my favorites is referenced in O Brother Where Art Thou? when Penelope asks Everett to find her ring at the bottom of the new Arkbutla lake created for the hydroelectric project in the rural South.
In Bacchylides’ dithyrambs, he tells us that Theseus lands in Crete, and Minos starts being obnoxious (as is to be expected), getting all handsy with the young Athenian women that were brought as tribute. Theseus was not having that:
Son of greatest Zeus, the spirit you guide in your heart is no longer pious. Hero, restrain your overbearing force. Whatever the all-powerful fate of the gods has granted for us, and however the scale of Justice inclines, we shall fulfill our appointed destiny when it comes. As for you, hold back from your oppressive scheme. It may be that the dear lovely-named daughter of Phoenix went to the bed of Zeus beneath the brow of Ida and bore you, greatest of mortals, but I too was borne by the daughter of rich Pittheus, who coupled with the sea-god Poseidon, and the violet-haired Nereids gave her a golden veil. And so, war-lord of Knossos, I bid you to restrain your grievous violence; for I would not want to see the lovely immortal light of Dawn if you were to subdue one of these young people against her will. Before that we will show the force of our arms, and what comes after that a god will decide.”
And Minos goes “Okay. If you’re the son of Poseidon, then your father can help you get this ring out of the depths.” And he throws the ring into the sea. So Theseus is kind of terrified because he doesn’t know if he’s a demigod, and there’s a lot of waves. But he quashes his fear and jumps in, and the sea opens for him, and all these mermaids and dolphins start singing, and he’s carried down to hang out with Poseidon, who also isn’t sure he’s his son, but would rather err on the side of him being his. So Theseus gets the ring and some fatherly love, and comes back up and Minos is like, “Okay get in the maze. Nothing to see here.” You can read the whole thing (in translation) here.
Theseus is the king of being tricksy, and on his way to Athens he tricked several cthonic (Underworld) monsters/bandits. The first one was Periphetes, who tried to kill his challengers with a club. Theseus basically took it away from him and killed him. Next was Sinis, whose method of killing he criticized as ineffective, convincing Sinis to demonstrate it. Sinis was torn apart by his own creepy torture device. Most of the other monsters Theseus fought had similar sinister torture devices, and they kept falling for Theseus’ “but how does it work?” line or getting beaten into submission.
Theseus battled the centaurs at his best friend Pirithous’ wedding after they got too rowdy on the wine and started trying to kill guests. I think this teaches us that the Lapiths have the best (and worst) parties ever.
You can get Theseus’ full biography by Plutarch here. Also, it’s probably worth checking out Chaucer’s The Knight’s Tale in which Theseus is a main character, the catalyst for the heroics of the title character.