Cardiff Blues
Last season: 7th
Best finish: 2nd (2006/07 & 2007/08)
Ins: George Earle (Scarlets), Rhys Gill (Saracens), Willis Halaholo (Hurricanes), Matthew Morgan (Bristol), Kirby Myhill (Scarlets), Nick Williams (Ulster), Rhun Williams (RGC).
Outs: Elis Wyn Benham (released), Gareth Davies (Merthyr), Harry Davies (Bath), Tom Davies (Dragons), Chris Dicomidis (Pontypridd), Gavin Evans (Neath), Sam Hobbs (Dragons), Tom Isaacs (Hong Kong Football Club), Craig Mitchell (Dragons), Miles Normandale (Rotherham), Rhys Patchell (Scarlets), Lou Reed (Sale), Richard Smith (Scarlets), Manoa Vosawai (RC Vannes), Tom Williams (Scarlets).
Newport Gwent Dragons
Last season: 10th
Best finish: 3rd (2003/04)
Ins: Sam Beard (Edinburgh), Tom Davies (Cardiff Blues), Darran Harris (Rotherham), Sam Hobbs (Cardiff Blues), Patrick Howard (Northampton), Nick Macleod (Sale), Craig Mitchell (Cardiff Blues), Ashley Sweet (Ebbw Vale).
Outs: Andrew Coombs (retired), Taulupe Faletau (Bath), Hugh Gustafson (Ospreys), Matthew Pewtner (retired), Jason Tovey (Edinburgh).
Ospreys
Last season: 8th
Best finish: 1st (2004/05 and 2006/07) and champions (2009/10 and 2011/12)
Ins: Bradley Davies (Wasps), Kieron Fonotia (Crusaders), Hugh Gustafson (Dragons), Rhodri Jones (Scarlets).
Outs: Rynier Bernardo (Scarlets), Ifereimi Boladau (London Scottish), Jordan Collier (released), Gareth Delve (released) Matthew Dwyer (released), Lloyd Evans (released), Richard Fussell (backs skills coach), Rhodri Hughes (released), Aaron Jarvis (Clermont Auvergne), Aled Jenkins (released), Kristian Phillips (London Welsh), Marc Thomas (Jersey Reds).
Scarlets
Last season: 5th
Best finish: 1st (2003/04)
Ins: Tadhg Beirne (Leinster), Rynier Bernardo (Ospreys), Jonathan Davies (Clermont Auvergne), Jonathan Evans (Bath), Werner Kruger (Bulls), Johnny McNicholl (Crusaders), Rhys Patchell (Cardiff Blues), Richard Smith (Cardiff Blues), Tom Williams (Cardiff Blues).
Outs: Michael Collins (released), George Earle (Cardiff Blues), Kieran Hardy (Jersey Reds), Phil John (released), Jack Jones (Llanelli), Rhodri Jones (Ospreys), Regan King (Jersey Reds), Ben Leung (Cardiff), Josh Lewis (Ebbw Vale), Connor Lloyd (Carmarthen Quins), Torin Myhill (Carmarthen Quins), Maselino Paulino (Lyon), Jack Payne (released), Harry Robinson (retired), Steven Shingler (Cardiff Blues), Michael Tagicakibau (Treviso), Jordan Williams (Bristol), Rhodri Williams (Bristol).