Monica and Chandler forgot about their pact for this year's Valentine's Day to exchange only homemade gifts because these are supposedly more personal and more fun.
Joey is struggling money-wise by working as a waiter at Central Perk, so Ross suggests some alternative form of employment. Joey wants to participate in medical studies at the hospital. He finds one that pays a lot for identical twins, so he organizes an audition and hires Carl to pose as his twin. Carl is even dumber than Joey.
Rachel and Phoebe take a self-defense class for women together. Ross scoffs at them and claims to have years of karate experience. He insists he's a master the true essence of self-defense: "unagi", which Ross believes is "a state of total awareness".
- Abuse Mistake: After getting humiliated by the girls, Ross reaches out to their self-defense instructor for help, but phrases it out of context making him sound like a psychopath who enjoys assaulting women.
- Artistic License History: Ross mentions that Apollo 8 orbited the moon twice. It actually made ten orbits.
- Closeup on Head: As Joey considers how to find a twin for the study, the camera pulls back to show him at an audition, where all the other actors are dressed like him.
- Crappy Homemade Gift: Played with. Chandler and Monica decide to give each other homemade gifts for Valentine's Day, but they both forget. Chandler gives her a mixtape he found at the bottom of his drawer and claims he made it, while Monica's "gift" was much less impressive (a sock puppet bunny she got from Phoebe). She's so impressed by the mixtape that she showers him in gifts and food, which he's happy with, but then they decide to actually listen to it... and she discovers the tape was one Janice gave him, bringing the gift right back around to being crappy.
- Curtain Camouflage: Rachel and Phoebe successfully hide from Ross behind a curtain and scare him by jumping out and yelling "Danger!" Later, Ross tries to get them back the same way, but they see the top of his head from behind a chair. Next shot is Ross being subdued by the two girls.
- Didn't Think This Through: Joey's entire plan hinges on no one noticing that someone who doesn't look identical to him could be his identical twin.
- Five-Second Foreshadowing: When Chandler shows up at Ross' apartment the viewer can spot bulges in the curtains where Rachel and Phoebe are hiding. Their presence isn't revealed until several minutes later after Chandler leaves.
- Groin Attack: Discussed when Rachel and Phoebe come back from self defense class.Rachel: Kicking a guy in the crotch all day really takes it out of you.
Joey: Takes it out of you? Heh.
- Identical Stranger: Parodied with Joey getting Carl to pose as his identical twin, even though the two clearly look nothing alike.
- Ironic Echo: "DANGER!"
- I Was Beaten by a Girl: Ross is thoroughly humiliated by Rachel and Phoebe at self defense. Then by two random women in the credits.
- Know-Nothing Know-It-All: Ross claims to have "unagi", which, as Rachel and Phoebe point out, actually means "freshwater eel". He actually means "zanshin", which does indeed mean "a state of total awareness." (He might have confused it with "ura nage", which is actually a judo term.)
- Lampshade Hanging: Chandler and Monica point out the very obvious ways Joey's plan is doomed to fail.
- Laser-Guided Karma: Both Chandler and Monica forget about their late Valentines gifts to each other being homemade until the last minute. When Monica is forced to confess she forgot, rather than admit he did the same and his mixtape was grabbed at the last minute, he decides to take advantage of her buttering him up as an apology. Karma strikes when they actually listen to the tape and Janice's voice pops up revealing it was actually a birthday present for him.
- Mangled Catchphrase: To test out his "twin" Carl, Joey makes the guy get into Monica's apartment to get a soda from the fridge, all the while Monica and Chandler look at him flabbergasted.Carl: Hi, Mon! Heeeey, Chan! Just getting a soda.
Monica: Who the hell are you?
Carl: I'm Joey! (beat) How are you doooooooiiiing?
Joey: (entering the room) NO, NO, NO, NO, NO! How YOU doin'? How you doin'? DAMMIT, Carl, go wait in the hall!
- Mistaken from Behind: In The Tag, Ross think he sees Phoebe and Rachel from behind and tries to attack them one last time. Meanwhile, the real Phoebe and Rachel watch from the window of Central Perk as Ross attacks two total strangers... and then runs away from them as they strike back.
- Mixtape of Love: Chandler desperately searches for a last minute homemade Valentine's Day gift for Monica and finds an old mixtape. Unfortunately, it's revealed to be a gift from his ex-girlfriend Janice, which is made clear when a lovey dovey message recorded in her screeching voice pops up in the middle of "My Funny Valentine".
- Never My Fault: Upon his very obviously flawed plan not working, Joey angrily shouts, "Dammit, Carl!"
- Once a Season: Janice makes her traditional yearly appearance, albeit as a voice only and not in person.
- Screams Like a Little Girl: Ross after being surprised by Rachel and Phoebe.
- Screw This, I'm Outta Here: In the end credit sequence, Ross sees two women from behind, mistakes them for Rachel and Phoebe, and tries another attack. Upon realizing his mistake, he runs screaming from two now very angry women.
- Take That, Us: The episode opens with Ross remembering the time he got Marcel and asking "what the hell was I thinking?"
- A Taste Of His Own Medicine: Ross tries to prove his point to Rachel and Phoebe by jumping out from hiding and screaming, "DANGER!" They panic instead of fight, so he feels validated, but they return the favor in his apartment. When he tries to get back at them in their apartment, they can see where he's hiding, which results in Beaten By A Girl.
- That Came Out Wrong: Ross goes to the self defense class and asks the instructor for tips on how to counter Rachel and Phoebe's attacks.Ross: About that last move where the woman tripped you and then pinned you to the floor, what would you do next?
Instructor: Well, she would try to take her keys and then jam...
Ross: No, no, what would you do next?
Instructor: Who, me? The attacker?
Ross: Yes, that's right.
Ross: I tried attacking two women. Did not work out.
Ross: It's okay. I mean, they're my friends. In fact I was married to one of them.
Instructor: Let me get this straight. You attacked your ex-wife?
Ross: Oh, no, no, no. I tried.
- Valentine's Day Episode: Monica and Chandler celebrate Valentine's Day two weeks later because Monica was working on Valentine's Day.