Lego has become "significantly more violent" and goes against the world's largest toy maker's non-violent, family-friendly ethos, scientists say.
Lego, often voted the greatest toy of all time, is designed to enrich play with engaging conflict scenarios where aggression might be used for the purpose of overcoming imaginary evil.
But University of Canterbury researchers have identified increasing violence in the Danish toy giant's products that "seems to have gone beyond simply enriching game play".
The research found that the violence of products highlighted in Lego catalogues has increased by 19 per cent every year from 1978 to 2014.
Currently, around 40 per cent of all pages contain some type of violence, with many scenarios involving shooting and threatening behaviour.
Almost 30 per cent of Lego sets now include at least one weapon brick.
The Lego Company's products are not as innocent as they used to be, says lead author Dr Christoph Bartneck.
"The Lego company often claims that their violence normally happens within a humorous context, yet the results show that humorous is the least likely atmosphere," he said.
"Material harm is the most frequent consequence of the violent acts followed by mild harm or injuries."
The research project, published this week in the international scientific journal PLOS ONE, was a collaboration within the University of Canterbury between its Human Interface Technology Laboratory New Zealand (HIT Lab NZ), the departments of English and the Digital Humanities in the College of Arts, and the department of Mathematics and Statistics.
HIT Lab NZ is now looking to conduct further studies on violence in traditional media and virtual reality games.
Last year, a study found that Lego's branded kits, such as the Star Wars packs which come with instructions, hamper children's creativity.
Norwegian scientists gave children kits with step-by-step instructions while others were left to build what they wanted. Both groups were later given other creative tasks.
Those who had no instructions with the Lego outperformed the other group in the creativity tests, the study found.