As part of Orientation activities, students enjoyed some tug-of-war fun amid the mud at the college of residence on Saturday morning.
Later, many also took part in the annual Water of Leith run, a tradition begun in 1935.
At the weekend, female students carried a bath, once "borrowed" from Knox College, to the Dunedin Botanic Garden.
Male students from Selwyn then carried the bath along the Leith - while being pelted with eggs by student onlookers - to the university clocktower area.
There the bath runners emerged, tired but happy, from the stream.
Organisers said that, as part of preparations for the latest Leith run, many bottles and other potentially dangerous rubbish had been removed from the Leith.
Chris Brewer (19), a second-year student at Selwyn, said the bath-carrying run had been "a really good bonding experience for everyone" taking part.
