J'Accuse is a detective game, for those who like their mysteries fraught with hilarity.
You need at least, oh, 7 people. We played it at Esalen with 32.
Everyone starts the game milling around. Shaking hands randomly. Engaging in idle conversation. While the whole lot of handshaking is going on, the referee (or whatever you want to call the person who's teaching the game), selects someone to be the murderer. This is accomplished by means of a secret hand shake, known as the "palm tickle."
The murderer commits the heinous crime by means of a similarly secret, but this time poisonous palm tickle. It's a slow-acting poison, and the dying are encouraged to delay their death throes by at least several seconds. Of course, the dying are further encouraged to engage themselves in the full range of contortions and gasps normally accompanying death by drama.
If you think you know who the killer is, you shout "J'Accuse." You don't actually do anything at this point. Everyone immediately refrains from any further handshaking and milling. According to the rules, nothing happens until someone else says the equivalent of "J'Accuse, Too." In other words, an accusation is not a true accusation unless it is seconded. At that time, both the first and the seconder point at the accused. If they point to the same person, that person must reveal his or her true identity. If not, they are both dead, and entitled to dying as horrible a death as they deem advisable. If the first is not seconded, he or she too must die..
And so the ever more fortunate and dwindling few meander into the depths of feigned fear and frank frolic, whilst the dead play smugly dead...until the murder is brought to justice or there are only three left amongst the living.
The person who was murderer the last round selects the murderer for the next, in much the same manner.