“Warcraft” (** out of four) was a visually dazzling but dull, derivative adaptation of the popular video-game series set in the peaceful world of Azeroth which becomes under siege from a race of invaders. When a portal opens connecting the two separate worlds of the civilization, one army faces destruction and the other faces extinction. Proof that you can have all the special effects and production work that money can buy but it’s all empty unless there’s a story and characters you care about. Visual effects are impressive but you’ll be satisfied after about a half hour. Hardcore video-game junkies may find more substance here.