Teen tried to talk student out of stabbing

The friend of a Queensland boy on trial for stabbing a classmate says he tried to talk his mate out of committing the violent act.

The 16-year-old testified at the trial of his former best friend in the Brisbane Supreme Court on Tuesday.

The accused was 14 when he stabbed a fellow Year 10 boy in the neck at a Brisbane school in August 2013.

He has pleaded guilty to unlawful wounding but not guilty to charges of attempted murder, and wounding in an attempt to maim or disfigure.

Under cross examination, the witness agreed his friend had told him just before the stabbing he was going to kill the classmate.

"I still didn't take it very seriously," the teen testified.

He agreed he spent about 20 minutes trying to talk his friend out of it, saying things like: "it's not right", "this is bad" and "think how this will affect you".

The witness also agreed the accused described doing internet searches on his computer that would make him appear crazy.

He said he recalled the accused had a list of names titled "soul list" and the victim's name had been ticked off.

"I just thought it was a joke," he testified.

He agreed his friend liked to sneak up on people and scare them, and that he had a passion for violent video games, including ones that involved players collecting souls.

Medical experts testified the classmate's stab wound travelled 5.5cm under the skin but was superficial and no vital structures were harmed, and he was released from hospital the following day.

A student who was in Year 8 at the time told police he'd seen the stabbed boy in the auditorium grasping his neck with his hand.

"He pulled it away and it was very much covered in blood," the boy said in a recorded interview played in court.

The trial continues.