A man has been thrown out of a national showcase of role-play gaming after alarming players by leading them through a scenario in which their characters were raped.
UK Games Expo has been welcoming visitors and exhibitors to the NEC near Birmingham since Friday.
But during one role-playing game (RPG), the person who controls the storyline described sexual abuse which one female player called "appalling".
Organisers have apologised to her.
On Twitter she said it was the worst RPG experience of her life, adding the game master (GM) "decided it would be perfectly all right to have all our characters kidnapped and gang-raped without discussing it with anyone first".
She said the GM "told us he enjoyed the shock factor of it".
UK Games Expo says it is the UK's largest hobby games convention.
A statement said: "It was brought to our attention that in an RPG game on Friday afternoon, a GM volunteer included content that was completely unacceptable and breached both the letter and spirit of the UK Games Expo.
"The scenario included descriptions of sexual violence involving the players. The players were understandably distressed and shocked by this content."
It added the player who raised the issue had received an "unreserved" apology "for the distress caused", and the other players were being contacted to offer "any assistance they might need".
UK Games Expo said the content was not set out in the game description and was unacceptable even for one with an 18 rating.
The GM has been ejected from the show, which runs until Sunday, and is banned from future events.
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