Downloadable content, known to video gamers as “DLC,” is additional stuff you can download after you’ve purchased a game. It could be additional game levels, playable characters, costumes, more songs for games like “Rock Band 3” or other virtual material.

DLC usually isn’t free. Sometimes game companies package together bundles of downloadable content to sell to those who don’t want to purchase the assorted pieces separately online. Some companies have found they can afford to give away video games for free online and make their money on DLC alone.

Pricing of DLC can be controversial, especially if gamers think it’s material that should have already been included with a pricey game. But in other cases, DLC can extend the life of a game by offering additional ways to play and more story. In the case of “Mass Effect 3,” one piece of DLC called “Leviathan” even changed and clarified the ending of the trilogy after complaints from players.

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