In
the play while Rosencrantz and Guildenstern are headed to meet the
king they both know what their fate awaits them. Since they are use
to let things happen and do not take control over their own lives;
they resort to gambling and rationalizing to avoid any guilt.
The
events that led to their demise started from the delivery of the
letter to them. That letter had the order to kill hamlet. But hamlet
changed it to condemn both Rosencrantz and Guildenstern. After they
realized their situation they just spent their last moments thinking
what they had missed that led to this.
I
hope this helps, Regards.