Blindfolded solving (abbreviated BLD) is the discipline of memorizing the position a puzzle is in and then solving it without looking at it again. The times for these events must include both the memorization stage and the solving ('execution') stage. Blindfolds are used to block a cuber's vision during blindsolving. Another blind solving discipline called speedBLD allows unlimited memorisation time, and favours methods which are fast to execute, rather than easy to memorise. For hardcore BLD solvers, another variant called multiple blindfolded involves trying to blindfold solve as many cubes as possible.
Official Blindfolded Events
The WCA currently recognizes four official blindfolded events: 3x3x3, Multiple 3x3x3, 4x4x4, and 5x5x5.