[Mobhack]

Edit the relevant OObs and deduct 2 from all movement to allow for wearing Noddy suits, being closed down AFV etc, leaving at least 1 MP for lower (guns, mortars) if you desire.

NBC adds time and effort (try digging a trench in noddy suits in summer - I have!) but it does not really have any "killer" effects except on the unprotected - third world armies, civilians etc. And even in that case - the user army has to suit up to enter the "slimed" areas.