Three Canberra men accused of plotting to kill one of their friends in 2008 have gone on trial in the ACT Supreme Court.

The crown prosecutor opened the case by describing the moment a woman in Tuggeranong woke to discover a 17-year-old man lying exhausted and injured on her doorstep.

It came at the end of a three hour ordeal for the teenager, who had been beaten with a baseball bat and chased through bushland.

Police say the victim was never meant to survive the night.

Officers allege his three friends intended to wrap his body in a curtain and hide it in the boot of his friend's car.

Alexander Raymond Iacuone, 23, and a man who can not be named have admitted to the assault but denied planning the murder with a third man Alexander James Duffy, 24.

The trial for all three is expected to continue into next week.