Analysis:

• Royal Caribbean claims that there is benefit by Avi (free vacation) and loss by Royal (because it takes the spot of another passenger), so it would be a case of זה נהנה וזה חסר so Avi would be obligated to pay.

• Avi then argues in court that Royal did not lose because no more people can embark on the cruise ship in Puerto Rico. Therefore, it would be זה נהנה וזה לא חסר.

• Does Avi truly benefit?

  • If Avi was sleeping on the streets of Puerto Rico before the ship arrived and he was not paying rent, then he does not benefit from staying on the cruise ship for free because he could have stayed in Puerto Rico for free.

    • If Avi doesn’t benefit and Royal doesn’t lose, it is זה אינו נהנה וזה לא חסר and Avi would not have to pay.

    • If more people could have embarked on the Royal had loss, it would be זה אינו נהנה וזה לא חסר so Avi would have to pay according to the רי“ף (Must pay because there is loss) and would not have to pay according to Tosafot (Pay based off of benefit, the loss is indirect)

  • If Avi was staying at a hotel in Puerto Rico, he would be benefitting from no longer having to pay for the hotel by staying on the ship which is זה נהנה וזה לא חסר.

• The Gemara offers 5 proofs if Avi should pay if there is benefit and no loss.

  • Proof #1: Since one pays for what an animal benefits when it eats in public property, Avi should have to pay what he benefited

    • Rejection: Actually, In the animal case there was loss (food), here there is no loss

  • Proof #2: Rami Bar Chama says when someone surrounds another guy with property and build 4 fences around the property, the inside guy must pay for some when the 4th side is built, proving ‏זה נהנה וזה לא חסר is obligated and Avi would have to pay

    • Rejection: No! The reason inside guy has to pay is because he is the cause for the outside guy having to build the fences in the first place, so we are still unsure if Avi has to pay

  • Proof #3 from R. Yosi of same fence case: If the inside guy builds the last fence- he has to pay for everything, if the outside guy builds it, the inside guy is exempt → זה נהנה וזה לא חסר is exempt and Avi would not have to pay

• • • Rejection: The actual reason he doesn't have to pay is because he could have gotten a cheaper fence.

  • Proof #4 from Tana Kama (Attic case): Ong guy lives in attic/second floor of a house which burns down. The top guy wants to rebuild but the bottom guy doesn't. Top guy builds first floor and lives in it until bottom guy pays his due. The bottom guy does not have to pay rent → זה נהנה וזה לא חסר is exempt and Avi would not have to pay

    • Rejection: Attic guy really doesn’t need to pay rent because it's the owner’s fault for not wanting to build so we are still unsure if Avi has to pay

  • Proof #5 from R. Yehudah (Attic case): The top guy has to pay rent because he is living somewhere without the owner’s knowledge! זה נהנה וזה לא חסר is obligated! This seems very relevant to Avi’s case and shows Avi would have to pay!

    • Rejection: No! The reason the top guy would have to pay is because there is loss! The house is no longer new and loses property value (Blackening of the walls). Since Avi staying on the ship causes no damage and the value of the ship does not go down, there is still no answer!

  • The opinion of Rav Ami: Since there is no loss and no damage, there is nothing for Avi to pay!

• The Gemara then brings up another proof from Eboyhu in the name of Rav. Yochanan even though Rav Yochanan did not really agree.

  • Rav Eboyhu uses the case of a גזבר taking a הקדש to prove that that זה נהנה וזה לא חסר is חייב: Since the גזבר is חייב for מעילה even though there is no loss and there is benefit (God didn’t lose and he was able to benefit from the item), therefore, one should pay rent in the attic case and Avi would be obligated to pay Royal.

  • Rejection: ״הקדש שלא מדעת כהדיוט מדעת דמי״ “Without knowledge is like a regular person with knowledge.”

• Rashi: God made the rules and the moment the גזבר took it, God knew. הקדש without knowledge does not exist because God knows everything (Knowledge is power- once the owner knows someone is using their stuff, he is obligated).

• Tosafot: It doesn't matter if the owner knows about it or not, all that matters is if there is loss. The reason the גזבר violates מעילה is because God made the rule that the גזבר knew before - that if one benefits from הקדש, they violate מעילה.

• It seems from here that Avi would have to pay because Royals rule is for people to not come on the ship without paying but they didn't know about it as Hashem did in this case so there is still no answer.

• The Shulchan Orech gives the final ruling: Any house is established to be rented (even if it’s not normally rented out) still though, זה נהנה וזה לא חסר is is exempt (though there must be absolutely no loss though for it to be exempt)

  • Therefore Avi would have to pay Royal Caribbean for sneaking onto the cruise because there is some sort of small loss (like fuel) and Royal is established to be rented

But wait! There's more!

• What if Avi had a friend, Pablo, who worked on the ship as a Navigator on the bridge and Pablo had an extra bed in his room that he let his friends and friends of friends stay in for free. Avi knew Pablo normally did not rent out his extra bed but charged Gavi $200 to stay in that bed.

  • We learn from the נמוקי יוסף that Gavi does not have to pay at all because it was a mistaken sale because the bed was normally not rented out by Royal Caribbean or Pablo.

• What if, Avi knew it was easy to sneak onto the ship and sold Gavi a cruise for only $200 then snuck him into a normal stateroom which usually costs that is usually rented out for $750? Whom does Gavi have to pay and how much?

  • We learn from the Gemara 21a that if you rent a house from one person then find out someone else actually owns it, you have to pay the actual owner the rate the owner would have charged which is $750 to Royal ( נמוקי יוסף: it says “נמצא בית של שמעון מאלה שכר לשמעון” so must have to pay Shimon's rate because it says לשמעון)

  • נמוקי יוסף in the name of the רמ״ה: Since the Gemara focuses on the property rather than the squatter, the status of the property is the only detail that matters. Therefore, Gavi only has to pay Royal, not Avi, if the room is normally rented. In this case, the room is usually rented out for $750 so Gavi has to pay $750 to Royal

  • Therefore Gavi would have to pay Royal Caribbean the actual cost of going on the cruise