Aikido techniques multiple attackers
Multiple attackers and randori
One feature of aikido is training to defend oneself against multiple attackers. Freestyle (randori, or jiyūwaza) practice with multiple attackers is a key part of most curriculae and is required for the higher level ranks.[35] Randori exercises a person's ability to intuitively perform techniques in an unstructured environment.[35] Strategic choice of techniques, based upon how they reposition the student relative to other attackers, is important in randori training. For instance, an ura technique might be used to neutralise the current attacker while turning to face attackers approaching from behind.[2]
In Shodokan Aikido, randori differs in that it is not performed with multiple persons with defined roles of defender and attacker, but between two people, where both participants attack, defend, and counter at will. In this respect it resembles judo randori.[
Source : http://en.wikipedia.org/wiki/Aikido