这句话是祈使句的间接引语，写成：The doctor told me never to play computer games again.
祈使句通常用动词原形开头，变为间接引语的时候，动词原形前面加一个to，也就是用动词不定式引出，引述动词常常用tell、ask、order，如：
My mother told me to come at five o'clock.
My father told me not to give up my hope.
He advised me to give up smoking.
He suggested that I should give up smoking.
The teacher forbade us to leave our seats.
希望我能帮助你解疑释惑。
