Inducement to break a rule (4)
I believe the answer is:
lure
'inducement' is the definition.
(I've seen this in another clue)
'break a rule' is the wordplay.
'break' indicates an anagram.
'rule' anagrammed gives 'LURE'.
'to' acts as a link.
(Other definitions for lure that I've seen before include "Entice, bait" , "Tempt with bait" , "Tempt invoking rule" , "Temptation" , "'Decoy, bait (4)'" .)