A common trick the universities use is to tell candidates that they'll upgrade them from a conditional (e.g. AAB offer) to an unconditional offer if they make t

A common trick the universities use is to tell candidates that they'll upgrade them from a conditional (e.g. AAB offer) to an unconditional offer if they make that university their firm choice within X days. I believe it's a way for them to better predict how many students they'll have next year, otherwise it can fluctuate pretty wildly based on exam day results.