Exam with a fifty-fifty at the start - it's bland and unoriginal (9)
I believe the answer is:
wallpaper
'it's bland and unoriginal' is the definition.
(eg musical wallpaper - bland music)
'exam with a fifty-fifty at the start' is the wordplay.
'exam' becomes 'paper' ().
'with' becomes 'w' (abbreviation).
'fifty-fifty' becomes 'LL' (L is r0 in Roman numerals).
'at the start' is a charade indicator (letters next to each other).
'w'+'a'+'ll'='wall'
'paper' put after 'wall' is 'WALLPAPER'.
(Other definitions for wallpaper that I've seen before include "Bland and unoriginal stuff - for decorating" , "Screen background" , "Mural decoration" , "Pasted covering" .)