Activision Frat-House Culture Claims Spread to Delaware Court

A group of institutional investors sued Activision Blizzard Inc. in Delaware over claims—already the subject of enforcement actions, litigation, and widespread scandal—that the video game giant’s “1980s fraternity house” culture has made it a persistently toxic place for women to work.

The lawsuit, made public Thursday in Delaware Chancery Court, comes two days after the company’s employees staged a walkout, calling for CEO Bobby Kotick to resign over allegations that he failed to report sexual harassment, assault, and even rape allegations to its board of directors.

But the board, which has publicly backed Kotick, has only itself to blame for ...