Pokemon Go players have been involved in hundreds of police incidents since the gaming app phenomenon launched, the BBC has learned.
Robberies, thefts, assaults and driving offences were among 290 incidents recorded across England and Wales throughout July.
Lancashire Constabulary logged 39 incidents - the highest figure from 29 forces that provided data.
The force has reiterated safety advice for fans of the monster-hunting game.
A spokesman for Pokemon Go developers Niantic also urged people playing the game to "abide by local laws".
Data released to the BBC under the Freedom of Information Act revealed officers have dealt with complaints ranging from the disturbing to the bizarre.
In some cases Pokemon players have been victims of crime, while others have been accused of committing offences or being involved in antisocial behaviour.
Surrey Police attended reports of 30 people fighting after a Pokemon hunt turned into a brawl.
Officers in north Wales discovered a man had invited children back to his home "as he had lots of Pokemon at his address".
In Cheshire, concerns were raised about children walking over graves in a cemetery as they took part in the augmented reality craze.
Both Greater Manchester Police and the Met noted incidents of Pokemon "lures" being set up, as robbers used the game to distract victims before snatching their mobile phones.
British Transport Police recorded two incidents of children trespassing on railways while playing the game, while several drivers have been spotted playing the game behind the wheel.
Other incidents were less clear. West Midlands Police referred to someone being "offered sexual favours" but provided no further detail.
West Mercia Police recorded a "road accident while playing Pokemon" but declined to elaborate.
A woman contacted West Yorkshire Police concerned that Pokemon characters were trying to "get into her home".
Cumbria Police received a complaint regarding a picture posted on Facebook, in which "the image had been altered to depict the person as a Pokemon character".
In another traffic-related incident, officers in Surrey discovered nine cars "parked across a junction" while looking for Pokemon.
Police in Devon were called to reports of a motorist driving down one-way streets and "stopping in the middle of the road playing Pokemon".
South Yorkshire Police said a Pokemon player had been punched and had their phone taken by three "unknown assailants".
West Mercia Police recorded 32 incidents, the second highest total, while the forces with the joint lowest were Thames Valley and North Yorkshire, which each logged two incidents.
The majority of forces declined to specify how many arrests had been made, with several citing ongoing investigations.
Sgt Neil Dewson-Smyth, of Cheshire Police, said the figures were "worrying".
"It was out in America first and there seemed to have been a few problems there. Nationally and internationally I'm well aware of quite a few circumstances that have come up," he said.
"But for me the key message is do not play it while driving. It's a fun game, but play safe and don't put lives at risk."
'Avoid dangerous locations'
A spokesman for Niantic said the company takes the issue of "player safety" seriously.
"We encourage all people to be aware of their surroundings and to play alongside friends or family, especially when you're exploring unfamiliar places," he added.
"Please remember to be safe and alert at all times, don't drive and play, abide by local laws and respect the locations you visit."
Lancashire Constabulary said Pokemon players should never trespass on private land or put themselves in any sort of risk for the sake of the game.
"People should avoid potentially dangerous locations that could make you vulnerable to injury or become a victim of crime," a force spokesman said.
"Never enter any body of water. Pokemon do not appear beyond the safety of the shoreline. And don't enter derelict structures, unlit footpaths or alleyways."