All three "next-generation" home video game consoles--the Xbox 360, the PlayStation 3, and the Nintendo Wii--offer some degree of backward compatibility, meaning they can play game titles designed for their respective predecessors. Some do so better than others, but none of them are without caveats and exceptions. Backward compatibility stacks up as follows:

Microsoft Xbox 360: You can play several dozen original-Xbox titles on the Xbox 360--as long as they're on the list of compatible titles. Many of the popular Xbox games (Halo 2, Knights of the Old Republic, Ninja Gaiden, and so on) are included, but the majority--numbering several hundred--are not. Microsoft updates the list periodically, though, so if your favorite classic game isn't currently on the list, there's a chance it will be added eventually.

Because the Xbox 360 controller is configured nearly identically to that of the original Xbox, you'll have no trouble playing the older games on the newer console (assuming, of course, that they're on the list of supported titles). However, your existing saved games on an original Xbox cannot be transferred to an Xbox 360, so you'll be forced to start from scratch.

None of the accessories for the original Xbox (controllers, memory cards, A/V cables) work with the 360. See our list of must-have Xbox 360 accessories for some recommended upgrades.

Sony PlayStation 3: On paper, the PlayStation 3 was designed to play nearly all PlayStation 2 and PlayStation 1 games. But with a back catalog of several thousand titles, it's not surprising that the PS3's backward compatibility is somewhat less than 100 percent. Most PS2 and PS1 games apparently work fine, but some exhibit minor glitches or are altogether unplayable. You can see how individual games perform on the PS3 by plugging in the titles on Sony's PlayStation 3 support site. Note that Sony can (and likely will) fix the most glaring problems via future downloadable firmware updates to the PS3, so a title that exhibits problems now may be fixed in the future.

Because the PlayStation 3 controller is nearly identical to that of the PlayStation 2 and the PlayStation 1, there shouldn't be any control problems when playing older games (unless listed as such on the aforementioned Sony site). Games saved on older PlayStation models can be transferred to a PlayStation 3 with a memory card and Memory Card Adapter.

Some older accessories (A/V cables, the EyeToy) will work with the PS3, while others (controllers) will not. See our list of must-have PS3 accessories for more info.

Nintendo Wii: The Nintendo Wii is designed to play all GameCube titles (about 380 to date), and early indications are that it does so with impressive consistency. But there's a catch: to play the GameCube titles, you'll need a GameCube controller. Up to four can be connected to the Wii, just as with the GameCube. Moreover, to save your progress when playing GameCube titles, you'll need to plug a GameCube memory card into one of the two slots found on top of the Wii. But that also means that any games already saved on a GameCube can be continued on a Wii.

While all GameCube games, controllers, and memory cards should work perfectly on a Wii, some more obscure accessories--such as the GameCube's A/V cables or Game Boy Player attachment--cannot be connected. See our list of must-have Wii accessories for more info.

Nintendo DS: In addition to playing new dual-screen DS games, the Nintendo DS and DS Lite should play all of the hundreds of game cartridges designed for the Game Boy Advance and later Game Boy systems, including the Game Boy Advance SP and the Game Boy Micro. (The only exception: older, larger cartridges designed for the pre-2001 Game Boy models such as the Game Boy Color.) Because the DS and DS Lite include the same controls as the GBA models, games play identically to the way they do on the various Game Boy models. Likewise, because GBA games are saved on the individual cartridges themselves, any game saved on a Game Boy can be loaded and continued on a DS system.

While GBA games work seamlessly on a DS, GBA accessories (link cables, AC chargers, and the like) do not.