起 = establish
作用 = effect
起作用 = take effect
反(opposite) --> (opposite of positive = negative)
起反作用 = take opposite (negative) effect --> The opposite result of the intended goal = counterproductive
When your action cause a positive/productive effect, that is 起(正面)作用
When your action cause a negative/ counterproductive, effect, that is 起反面作用 = 起反作用
正面 in 起正面作用 is omitted because the term 'effect' is presumed positive.
Example:
突襲起了作用 -- The raid took effect (a positive effect/ result of improving the odds of winning)
突襲起了反作用 -- The raid took opposite effect (a negative effect/ result of worsening the odds of winning)
'到' in '起到作用' is a verb particle that indicates the verb is succefully completed