Voldemort made so many mistakes due to his overconfidence that I genuinely believe he overdosed on Felix Felicis.

From Half-Blood Prince:

“Oho,” said Slughorn again. Harry was sure that Slughorn had not forgotten the potion at all, but had waited to be asked for dramatic effect. “Yes. That. Well, that one, ladies and gentlemen, is a most curious little potion called Felix Felicis. I take it,” he turned, smiling, to look at Hermione, who had let out an audible gasp, “that you know what Felix Felicis does, Miss Granger?”
“It’s liquid luck,” said Hermione excitedly. “It makes you lucky!” The whole class seemed to sit up a little straighten Now all Harry could see of Malfoy was the back of his sleek blond head, because he was at last giving Slughorn his full and undivided attention.
“Quite right, take another ten points for Gryffindor. Yes, it’s a funny little potion, Felix Felicis,” said Slughorn. “Desperately tricky to make, and disastrous to get wrong. However, if brewed correctly, as this has been, you will find that all your endeavors tend to succeed . . . at least until the effects wear off.”
“Why don’t people drink it all the time, sir?” said Terry Boot eagerly.
“Because if taken in excess, it causes giddiness, recklessness, and dangerous overconfidence,” said Slughorn. “Too much of a good thing, you know . . . highly toxic in large quantities. But taken sparingly, and very occasionally . . .”
“Have you ever taken it, sir?” asked Michael Corner with great interest.
“Twice in my life,” said Slughorn. “Once when I was twenty-four, once when I was fifty-seven. Two tablespoonfuls taken with breakfast. Two perfect days.”

 

Thats an interesting idea. However I don't think you could say he acts giddily at any point? Even reckless isn't the way I'd describe him. His plans seem too well thought out for that description.

 

I think he was reckless in his final moments when he removed the protection orb around Nagini and tried to kill Harry with a wand that wasn't loyal to him.

 

Hot take! I like it. I think this would work well in a fic that explored Voldemort's mistakes - especially from his POV.

Perhaps his altered appearance was due in part to altering himself in a way he believed would make him able to take more of the potion (among all the other ways you could enhance yourself by shedding more of your humanity I suppose - classic!). He thinks he's managing to get past the toxicity and has thwarted the side-effects but in reality, it is affecting him - just in ways he can't see. It's a fun reason to descend into madness.

I think Voldemort could really be fleshed out as a character by some hubris-induced self-reflection.

 

On the one hand, I don't think this actually fits canon Voldemort's personality quite well. As was mentioned, he lacks giddiness, and I imagine the effects of Felix overdose would more closely resemble Harry's attitude under the influence taken to an extreme. But on the other hand, I can't think of a better explanation for the movie scene where he hugs Draco, so it addresses that, at least.

 

You could argue that Voldemort's giddiness didn't manifest with the traditional giggling and skipping, but in his overuse of the torture curse on his subordinates (or rather his extreme inclination to melodrama). Would add a certain something to all those fanfic scenes where he Crucios his minions like he's giving out party favours.

 

This is a unique concept that I haven't seen before, but Voldemort seems too canny to depend on Felix Felicis. Especially when we consider V.'s philosophy of Machtpolitik (e.g. "There is only power and those too weak to seek it."), it seems to me that relying on luck is out of character for him. Luck is a factor he cannot control and Felix Felicis becomes less useful over time, so he definitely couldn't control luck by abusing the potion. The accumulation of power, however, can minimize the opportunities that might arise where luck would hurt him. This theory seems similar to the fanon idea that V. becomes gradually less sane/stable with the creation of each Horcrux.

 

Yes but Slughorn implies that 4 tablespoons are the most you can safely drink in your lifetime. Voldemort might have believed himself superior to that limit, more resistant to the side effects of the potion, and then he drank an additional dose for a total of 36 hours worth of luck, after that he became overconfident. Voldemort is always pushing the limits of magic, I think it's quite within his character to experiment like that.

By the way, thank you everyone for the feedback on this thread so far.

 

Personally I've always chalked it up to drinking unicorn blood in the first book, thereafter cursing him in spirit since it was technically his host who consumed the physical blood.

Treating it as Felix induced madness could be a fun direction to explore, however. I'll give it more thought and see where that leads.

 

Makes me wonder what someone like Rorscach's Blot could do with this premise.