Turn back and rescue half from the monsters (5)
I believe the answer is:
ogres
'the monsters' is the definition.
('ogre' can be a synonym of 'monster')
'turn back and rescue half' is the wordplay.
'turn' becomes 'go' (a person's move in a board game**).
'back' is a reversal indicator.
'and' says to put letters next to each other.
'half' suggests halving the letters.
'go' back-to-front is 'og'.
'rescue' cut in half is 'res'.
'og'+'res'='OGRES'
'from' is the link.
(Other definitions for ogres that I've seen before include "Giants in fairytales" , "'Monsters, fiends (5)'" , "Terrifying types" , "huge figures" , "Giant types" .)