Norway's confessed mass murderer Anders Behring Breivik told the court trying him on Thursday he only had a slim chance of surviving his bomb and shooting rampage.
A total of 77 people were killed in the twin attacks on 22 July 2011.
Breivik, who styles himself an anti-Muslim militant, said he had expected to be confronted by armed police when he left Oslo for a Labor Party youth camp on Utoya island, where he killed 69 people in a shooting massacre.
No one stopped Breivik as he drove to the island dressed in a homemade uniform. He was armed with a rifle and a handgun he had named after weapons used by the gods of Norse myth.
However, on this the fourth day of his trial, Breivik seemed disconcerted and dispensed with the clenched-fist salute he used in previous hearings.
He told the court he had prepared for a firefight with police in Oslo by playing computer games, focusing on situations where he would be flanked by two commando teams.
"I estimated the chances of survival as less than 5 percent," he said.
Cutting off social contact for a full year helped him prepare for the attacks, but said the game-playing was "pure entertainment. It doesn't have anything to do with July 22."
Breivik has confessed to the attacks but rejects criminal culpability, saying he was defending Norway by targeting left-wing political forces he claims have betrayed the country by opening it up to immigration.
On Tuesday he broke down and cried on the stand after complaining about "multicultualism" in Norway saying "my country is dying."
The key point of contention between Breivik and prosecutors is whether he is criminally insane.
Breivik claims to have carried out his attacks on behalf of an alleged anti-Muslim group called the Knights Templar, which he describes in a 1,500 page manifesto he posted online.
"In principle it is not an organization in a conventional sense," Breivik told the court, describing the Knights Templar as a leaderless network consisting of "independent cells."
Prosecutors told reporters on Wednesday that they don't believe the group is real or that the meetings Breivik claims took place in Liberia, Britain, and the Baltic countries ever happened.
If found sane, Breivik could face a maximum 21-year prison sentence or an alternate custody arrangement that would keep him locked up as long as he is considered a menace to society.
If declared insane, he would be committed to psychiatric care for as long as he's considered ill.
Breivik, however, rejects that he is insane and called for the death penalty should he be convicted.
"Acquittal or the death penalty are the only logical outcomes of this case," the confessed killer said. "I view 21 years in prison as a pathetic sentence."