Dundee University scientists have called for mandatory protective rugby headgear after a study showed it can cut impact levels by almost half.
The research showed that even the least effective device tested could make a "significant difference" in preventing head injuries, such as concussion.
The team said the study made a "compelling case" for protective headgear at all levels of the game.
The findings have been published in The BMJ.
The study was carried out by the university's institute of motion analysis & research (Imar).
Imar director Prof Rami Abboud said: "You cannot avoid injuries in contact sport and we are not saying that headgear would eradicate head injuries.
"But this research has shown just how significant a difference these products can make in helping to minimise the risk that rugby players face on the field."
Prof Abboud said that relatively simple devices could make a "significant difference" in protecting players, but some seemed reluctant to wear them.
He said: "If it became mandatory to wear these then the element of choice would be removed and further injuries could be prevented."
Seven devices were tested in the survey with force being decreased by 47% in the most effective headguard, and 27% in the least effective.
Final-year medicine student Erin Frizzell, the study's lead author, said she had been surprised at the effectiveness of all of the products tested.
"Across the range, the effectiveness was greater than I thought it would be, though the difference of 20% protection between the best and worst-performing was also an eye-opener."