Q. My friends are renting a hotel room for vacation and they offered to let me sleep on the floor. I can't afford a vacation otherwise. Can I take them up on their offer?
A. Hotel managers have many good reasons for charging by the guest and not allowing additional guests to stay over. We can find precedents for these in Jewish law.
The mishna states: "Someone who has a house in an adjacent courtyard may not open it up to this courtyard." The Talmud explains that this creates excessive traffic in the yard. The situation is someone who owns a house in each of two adjacent common courtyards. If he allows the residents of house B to use the entrance and courtyard of house A, then the other residents using courtyard A find that their courtyard is now overcrowded. (1)
Maimonides writes, "From this we can learn that if one resident brings other tenants into his house, his neighbor can prevent this, because he increases traffic. And the same holds for someone who rents a house from someone else and brought in relatives and friends to live together with him, the landlord can object." (2) Since the landlord doesn't necessarily live together with the tenant, later authorities inferred that increasing traffic is only one reason for this limitation. Another reason is that having more tenants increases wear and tear on the apartment. (3)
These reasons certainly apply to your situation. If hotel rooms are more populated, the common areas of the hotel become much more crowded as well. These areas are very expensive to maintain, and in addition when they are crowded it is an annoyance to paying customers. So the owner is entitled to get paid by the tenant, not just by the room.
In addition, there is no question that having more guests translates into more wear and tear – especially when we are talking about active young people who are known to be particularly hard on dwellings. For the young people themselves it's "the more the merrier", but it's well known that the premises do not always share in the merriment.
In the case of the hotel there is an additional consideration. If the hotel owner allows non-paying customers, then he will lose the income from customers who otherwise would pay. This applies even if the additional tenant imposes no costs whatever on the landlord. You personally can't afford a vacation without "a little help from your friends", but there are other people who could afford one but are happier taking a free ride.
This consideration too is discussed in Jewish law. The usual situation in rentals is that the landlord would be able to find another tenant and the tenant would have to pay to live in another dwelling. But sometimes this is not the case: some apartments are empty and not for rent, and some tenants have the ability to live elsewhere. The Talmud raises the question of whether the tenant has to pay in cases where he benefits but the landlord doesn't lose, or where he doesn't benefit but the landlord does lose. (4) All of the commentators understand that the landlord is within his rights to prevent a tenant from taking a free ride in this fashion. Maimonides explicitly states (in a slightly different context) that if the tenant's actions result in the loss of a paid tenant for the landlord, this is considered imposing a cost. (5)
If you want to go on vacation with your friends, you will have to find the money to pay your way. Your friends may not mind your imposition, but it's not fair to you to take a free ride at the expense of other guests and above all at the expense of the owner.
SOURCES: (1) Babylonian Talmud Bava Batra 59b. (2) Maimonides' Code, Laws of Neighbors 5:9 (3) Pitchei Choshen, laws of rentals 4:8 (4) Babylonian Talmud Bava Kama 20b (5) Maimonides' Code, Laws of Theft and Loss 3:9
The Jewish Ethicist presents some general principles of Jewish law. For specific questions and direct application, please consult a qualified Rabbi.