This is the standard (two-player) Prisoner’s Dilemma story:

          (a)      Two prisoners are held in jail separately and cannot communicate.

          (b)      The District Attorney has evidence that they jointly committed a serious crime, for which the penalty is six years in prison.

          (c)      However, this evidence is insufficient to convict either prisoner, in the absence of a confession by the other.

          (d)      But the D. A. has other evidence sufficient to convict each prisoner on a less serious charge, for which the penalty is two years in prison.

          (e)      The D. A. goes to each prisoner and offers the following deal (telling each the same offer has been made to the other): if you confess (implicating the other), I will take two years of whatever your sentence otherwise would be.

          (f)       Will either prisoner accept the D. A.'s offer? Would they choose differently if they could communicate?

          PRISONER 1