  We present Lode Encoder, a gamified mixed-initiative level creation system
for the classic platform-puzzle game Lode Runner. The system is built around
several autoencoders which are trained on sets of Lode Runner levels. When fed
with the user's design, each autoencoder produces a version of that design
which is closer in style to the levels that it was trained on. The Lode Encoder
interface allows the user to build and edit levels through 'painting' from the
suggestions provided by the autoencoders. Crucially, in order to encourage
designers to explore new possibilities, the system does not include more
traditional editing tools. We report on the system design and training
procedure, as well as on the evolution of the system itself and user tests.
