While droidekas do not walk very fast, they can move quickly by curling up into a ball and rolling, enable them to redeploy rapidly on the battlefied. They are armed with two double-barrelled, automatic blasters, making them powerful anti-infantry units. Some models carry shielding capable of resisting blaster small arms, but such droids can not move while their shields are active.
With their rapid fire and shielding, high-end droidekas could pose a significant threat to Jedi; the high volume of fire forced Jedi to focus their efforts on blocking shots with their lightsabres, and reflected shots would not penetrate the droid's shield. The droids' high cost, however, limited their production. They saw service during the Battle of Naboo and during the Clone Wars, but the were less effective against Clonetroopers with heavy rifles that could overcome their shielding. Like the rest of the Confederacy's droid armies -- they were deactivated at the Clone Wars' end.