Gender biases in fictional dialogue are well documented in many media. In film, television and books, female characters tend to talk less than male characters, talk to each other less than male characters talk to each other, and have a more limited range of things to say. Identifying these biases is an important step towards addressing them. However, there is a lack of solid data for video games, now one of the major mass media which has the ability to shape conceptions of gender and gender roles. We present theVideo Game Dialogue Corpus, the first large-scale, consistently coded corpus of video game dialogue, which makes it possible for the first time to measure and monitor gender representation in video game dialogue. It demonstrates that there is half as much dialogue from female characters as from male characters. Some of this is due to a lack of female characters, but there are also biases in who female characters speak to, and what they say. We make suggestions for how game developers can avoid these biases to make more inclusive games.