Due to our preference for using events from the Japanese version over dubbed events, videos of dubbed Yu-Gi-Oh! episodes are generally not used.
Videos are a touchier subject than images in terms of copyright. Only short clips should be used, whether they be used to illustrate an important plot point, card effect, Summoning sequence or anything else.
Episode previews can be used in their entirety, given that they are less than a minute long. Video game trailers may be used in a similar fashion.