The shock rifle can fire both the primary laser and the secondary shock ball. In an Instagib match all players start with a Super Shock Rifle, a weapon that kills any enemy player with just one shot. Combo InstaGib is the fun version of InstaGib DM. Instagib is a mutator featured in all Unreal games with a multiplayer aspect except for XMP.
When a shock ball gets hit by a shock laser it explodes with a large shock wave commonly refered to as the combo move.