The case in three lines. After a year of saving £127.50 a month, Tara collects the keys to her room in halls and is handed an inventory with fourteen lines, all ticked "good". Read aloud in the room, three of them are not: a scorch on the desk, a cracked tile and a stain on the carpet. A second-year down the corridor lost almost half her deposit for a mark she says was already there, and Tara has to write something in the comments box before she signs.

One question to ask. "What should Tara write?" Then: "Is it fair to make a fuss on the first day?" Let them argue both sides.

One thing to do at the table. Think of something you have borrowed or hired: a bike, a costume, a holiday flat. Ask how you would prove what it was like when you got it, if someone said later that you had broken it.

The grown-up layer. The case is about records made at the start: a dated, agreed account of how things were on the first day is what settles an argument on the last. It gives the warden his strongest point, that the hall is busy and fair. It gives the mother hers: nobody wants to start off on the wrong foot. The habits it models are reading every line before signing, photographing what you see with the date, getting the other side to hold the same record, and pricing what a missing line could cost.

The case leaves the line blank on purpose. Ask for it before you offer yours.