Nerf Speedball at Nerf Battle Zone is a competitive game using Nerf’s newest line of guns called the rival series. If you think that the regular Nerf guns are too soft and shoot too slowly for you, then you’ll love the new Rival Series. Think of it like paintball without the pain and mess. The Rival Series guns use small yellow balls instead of the classic Nerf darts, this means that the guns do not jam as much and are more accurate. The excitement and adrenaline rush from the Nerf Rival Series guns is almost on par with paintball & air soft; it’s like their little brother!