The Federal Trade Commission’s effort to stop Microsoft from buying video-game maker Activision Blizzard could chill tech mergers in the months ahead and force determined dealmakers to gird for a legal battle, legal experts say.

“Tech companies that enter into deals that raise competition concerns will have to be litigation-ready. The days of negotiating complicated consent decrees with behavioral conditions or debating the efficiencies of a vertical acquisition are behind us,” said Andre Barlow, a partner at Doyle, Barlow & Mazard in Washington, D.C.