In my dojo a shodan randori refers to anyone of that rank or higher attacking anyone of that rank or higher in multples. 2,3, or 4 against one nage. The attacks are limited to strikes, kicks, or grabs - no eye gouging and guns and knives are prohibited. Nage, of course, is also allowed any technique and/or atemi he can find.
If the attack is real, full speed, and full contact, then the defense is as well, and thus the ukes must be both well defined in their attack and able to take excellant ukime because nage sure isn't pulling his punches.
This kind of intensity is mandatory for all who wish to be udansha in this dojo. You must be fearless, and able to carry on despite being hurt or hindered. Sorry to whichever one of you said that this training can't be done. It is done every day here.
I might add that in ten years we have only had one person bow out for this. For that visitor, his choice was the wise one.