Has this scene variation ever happened in the movies or on television?

The scene is the one where one of two characters offers a drink, then secretly drops a small pill, a bit of powder or a small amount of liquid into the other person’s drink…only to have the other person secretly switch the drinks.
The variation I am interested in is where the switch is made…but after both characters have finished the drink the person declares that the pill/powder/fluid she/he dropped in the drink was the antidote to the poison already in both drinks.
Has this variation ever happened in the movies or on television?

Disenchantment has this as a major plot point of the first season. Bean’s mom was trying to get her dad, the king, to drink a petrification potion but the drinks got switched.

Did they use the specific variation I mentioned?

Oh, the antidote part? I must’ve dyslexoskimmed past that on first reading. Nope.

The Dune mythos has a residual poison that requires regular administration of the antidote to prevent it from taking effect. Baron Harkonnen had Thufir Hawat dosed with it.

I know there was one variation where the person poisoned both drinks with deadly Iocane powder, knowing he had previously built up an immunity.

How would this differ any from the straightforward variation, where A poisoned B’s drink, B switches the drinks, and then A dies? In your version, you still end up with one deadly drink and one safe drink due to A’s adulteration, and you still end up with A with the deadly drink due to B’s switch.

A’s drink wouldn’t end up deadly.

The difference is that the victim actually is poisoning her/him self unknowingly…with the added bonus of fooling the audience, too.

So, Alice offers Bob a drink, and she knows both drinks are poisoned, and she puts the antidote in Bob’s drink, keeping the poisoned drink for herself? What exactly is Alice’s motive here?

If there’s some sort of loving self-sacrifice going on, does Bob really know her so little, and like her so little, that he assumes she’s poisoning him, and switches the drinks so that (he assumes) she gets the poisoned one?

Guys, I don’t know of any antidotes that work that way. All the ones I can think of counteract the effects of a poison already in the body.

It’s like the question I heard back in the 50s: “What would happen if you mixed a bottle of nail polish with a bottle of nail polish remover?” (answer: Har de har, someone was trying to be Mitch Hedberg half a century early, but it doesn’t work like that.)

I believe this is referring to The Princess Bride (I saw this a couple weeks ago). This was the first movie I thought of. As mentioned, it is a variation.

Yes, this is the variation in The Princess Bride, in the Battle of Wits between The Man in Black and Vizzini.

The Man in Black challenges Vizzini to a Battle of Wits. He takes the two cups of wine before them, and a vial of Iocane powder (an odorless, colorless, tasteless, and utterly lethal poison), turns his back so Vizzini can’t see what he’s doing, and then turns back around. He puts one cup in front of Vizzini and one in front of himself. Vizzini then launches into a comedic masterpiece as he explains his convoluted reasoning as to which cup contains the Iocane powder. And then secretly switches the cups himself. They both drink, Vizzini gloats - and dies. The Princess Bride asks the Man in Black how he made sure Vizzini drank the poisoned cup. MiB replies to the effect that, oh, he poisoned both cups; he’d spent the last several years building up an immunity to Iocane powder. If you watch the scene carefully, MiB never actually says that one and only one of the cups was poisoned - that was all Vizzini’s assumptions and conjectures about what the Battle of Wits was, which the audience goes along with, because the set-up was such a well-worn trope.

Yes, it would, because A (presumably) intended A’s own drink to be safe, but B switched the glasses.

I guess you could have A deliberately adding the antidote where B could see it, but make it look like they were trying (but failing) to hide it, and then present both glasses in a neutral way and let B choose, with the intent that B would choose the one he saw didn’t have anything added, but that’s way unnecessarily complicated. What was A’s plan if B hadn’t been paying attention, didn’t notice the adulteration, chose randomly, and chose the wrong one? What if B, based on seeing A openly adding something to one drink, refused to drink at all, or drew a gun and shot A? Why even use antidote at all, instead of just secretly putting poison in one (since we’re assuming A was able to secretly poison both), and then openly add sugar to the other? If A has an antidote, why put it in the drinks at all, instead of just consuming it directly and reproducing the Princess Bride scene?

No, the OP has it that A put the antidote in B’s drink, and that B then switched the glasses.

Correct. Alice has the chalice with the pellet with the poison. Bob (what a slob!) switcheroos away the brew.

Uh, that is true.

Ah, yes, the OP does specify that it was the drink originally intended for B that had something added to it. In which case we must ask, as @Left_Hand_of_Dorkness does, why A was trying to poison himself.

This isn’t actually what happened. The reasoning Vizzini said out loud was not his actual reasoning. It was just what he wanted his opponent to hear, so he could get the data for his actual reasoning. Notice that, as his stated “reasoning” switched from one conclusion to the other, the Man in Black’s expression alternated between calm and concerned. Vizzini was reading his expression, and judging whether the concern was genuine or a bluff (or more precisely, whether it was an even-order bluff or an odd-order bluff). Which was something that he was in fact extraordinarily good at, to the point that (in the book), other characters frequently think that he’s telepathic.

That may well have been what happened in the book, but the movie doesn’t establish anything about Vizzini’s ability to read other people. In fact, he seems to be quite bad at that. I think he manages to misread literally everyone we see him interacting with. And he definitely misreads the Man in Black, and misunderstands the nature of the Battle of Wits.

I do think you’re right, though, that in that scene he’s trying to goad a reaction out of the Man in Black, and is looking for a tell. But I still think the convoluted reasoning and the way Wallace Shawn sells it is a comedic masterpiece.

Even this, I think, is a bluff. He’s got three levels going on:

  1. His superficial reasoning. This is 50% bluff, 50% him being an arrogant schmuck who can’t resist showing off how brilliant he is.
  2. His watch for tells. This is 80% real, 20% a distraction.
  3. His actual scheme, which is to switch the drinks and then watch what the Dread Pirate Roberts does when it’s time to drink. Everything else was leading up to this gambit, and an attempt to distract from it.

But in this scenario, both people want to survive the poison and have a plan for surviving. I understand Bob’s plan in Czarcasm’s scenario, but Alice’s plan is pretty unclear to me.

I’m not sure that any poisons or antidotes portrayed in the media actually work realistically. They are plot devices, distilled from the finest fruits of convenience.

As to the OP, I don’t know that I’ve ever seen that specific setup, but I do have to ask, is the reason that person B switches the drinks because they saw person A put a poison in, and is the reason that the saw person A put a poison in because person A intended them to?

For some reason, I vaguely remember some sort of slightly similar setup, except the antidote was to a poison that they had already both ingested. I kinda want to say it was on Babylon 5, with some Centauri intrigue, but I’m not really sure.