If you’re a lapsed “World of Warcraft” player looking for an excuse to relapse, this week’s expansion pack, “Wrath of the Lich King” ($40, rated T) should provide plenty of justification. “Lich King” adds a new continent to explore in the form of the lazily named frigid land of Northrend. Most interesting, though, is the addition of “WoW’s” first hero class, the death knight.

Unlike the game’s existing classes, you can’t just start off with a Level 1 death knight. You have to advance at least to Level 55 in another class, then become a death knight from there. In their preview of “Lich King,” IGN refers to the class as “front-line tanks . . . Cloaked in dark robes, death knights are an ominous sight on the battlefield.” Hopefully, the first hero class will beget others, allowing veteran players to find new ways to watch their free time circle the drain.

“Lich King” will also add Xbox 360-style achievements ” little rewards for accomplishing certain in-game feats. These digital merit badges sound like one of the hokiest, nerdiest trends in modern gaming, but if they’re anything like achievements on the 360, or trophies on the PS3, you’ll soon find they’re just another tool to make “WoW” even more addicting.

If it seems like there have been a ton of big-budget, M-rated shooters coming out for the Xbox 360 and PlayStation 3, it’s because there have been. With “Call of Duty: World at War” hitting stores, this week is no exception. But we’ll pause a few minutes from the carnage to take a look at couple more family-friendly games.

“Banjo-Kazooie: Nuts & Bolts” ($40, rated E10+) is an oddball, Xbox 360 exclusive that’s actually a sequel to a couple of Nintendo 64 titles. Developer Rare (now a Microsoft studio) has largely ditched the platform-to-platform style gameplay of the first two “Banjo” games in favor of a new approach that focuses on vehicle building. You’ll still play as Banjo the bear, traveling around a gorgeously vivid world with your sidekick, Kazooie the bird. This time out, though, you’ll scavenge for a variety of vehicle parts, assemble a crazy, rocket-powered car of your own design and travel off on fabulous adventures.

There hasn’t been another game quite like “Nuts & Bolts,” and it seems destined to end up a cult classic. The vehicle-building system is reportedly the kind of thing that people who love Legos will get lost in for hours, but it could leave many wondering what all the fuss is about. One warning: Apparently, the game’s text is nearly unreadable on a standard-definition TV. Like 2006’s “Dead Rising,” the game was reportedly programmed and tested using HDTVs, and no one thought to check to see how the game played on a regular old CRT set. The text is supposedly readable if you have a standard-def TV and your 360 is hooked up via an S-video cable. But if you’re using the red, yellow and white component cables, you might have to wait for “Banjo” to be patched.

Also out this week is “Mirror’s Edge” ($60, rated T), Electronic Arts’ parkour adventure title that looks a lot like a jiggle-free “Tomb Raider” for the 21st century. You play as Faith, who’s a courier in a totalitarian state that watches its citizens’ every move. You’ll leap and soar across rooftops to deliver messages, all the while trying to come up with a plan to free your sister from the government.

And yeah, “Call of Duty: World at War” is out this week. It’s rated M, costs $60 on PS3 and 360, $50 on Wii and PC. It’s developed by Treyarch, sort of the B team of the “Call of Duty” series, but it’s looking much better than their mediocre “Call of Duty 3.” It does, however, ditch the modern setting of the acclaimed “Call of Duty 4” for the somewhat shopworn World War II staging grounds. Hopefully, we’ll finish that war one of these days.