A primary school teacher who sent sexually explicit text messages to a 14-year-old boy whom she met through an interactive computer game was jailed for 12 months yesterday.

Lynn Walls, 42, first encountered the boy – who lived 240 miles away – while playing World of Warcraft, the world's most popular online game. In the role-playing game, which features humans and mythical creatures and has 11 million subscribers worldwide, Walls created a virtual self who was thin, attractive and blonde.

The overweight, divorced mother told police later that she had designed her virtual character to be “everything I am not”. The boy, from London, fell for the image. The pair had private discussions in an online chat room before Walls persuaded him to exchange mobile phone numbers.

Although he told her that he was 14, she showered him with a series of detailed, graphic text fantasies, encouraging him to commit sex acts and to send equally crude replies. Newcastle Crown Court was told that Walls, a teacher for 15 years, also told the teenager that she loved him and burdened him with her emotional problems, falsely claiming that she had breast cancer.

The relationship ended when the boy's father found his mobile phone and contacted the police.

Walls, from Penshaw, near Sunderland, was suspended and then sacked from her primary school. She pleaded guilty to inciting a child to engage in sexual activity.

Her victim was said to have been severely damaged by the experience, which had left him guilt-ridden. He lost self-esteem, was unmotivated at school and found it difficult to trust other people.

Penny Moreland, for the prosecution, said that the text messages sent by Walls in November 2007 were crude and explicit in the extreme. “As well as the sexual content it is apparent the defendant placed an emotional burden on this boy. She told him she loved him and she told him about her childhood difficulties. She told him about family problems and she told him, it seems falsely, that she had breast cancer.”

Miss Moreland added: “He expressed a feeling of guilt about her and feeling it was his responsibility to support her as she unburdened herself to him.”

The victim's mother said that he had changed from a happy boy with exemplary school reports to “a sad child”. He had voiced suicidal thoughts, became abusive to his mother and sister and was now receiving counselling.

Nick Peacock said in mitigation that Walls had led a blame-free life until her 20-year marriage ended with the discovery that her husband was having an affair with a colleague.

Her self-esteem collapsed, she “fell deeper and deeper into isolation” and began spending hours on the internet every day playing World of Warcraft. “Here was a woman who was seeking some sort of attention and she got it,” Mr Peacock said, adding that Walls accepted full responsibility for her actions and was “struggling to deal with the effect she has had upon her victim”.

Passing sentence, Judge Richard Lowden said: “It is not just the grossly inappropriate sexual content of the messages that has done the damage. To my mind more damaging was the emotional burden you put upon that boy. In the end he ended up feeling responsible for you and guilty himself of what had taken place between you.”

Walls was ordered to stay on the sex offenders register for ten years and banned for life from working with children.

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