There are a variety of other procedures to test for the occurrence of a foul. However, since any situation, any quality, or any function can be simulated in lucid dreaming, these procedures are not always applicable. For example, some suggest that it is sufficient to attempt doing something that is realistically impossible, and, if a practitioner is in lucid dreaming, the impossible action will be possible. The problem with this suggestion is that the laws of the physical world may be simulated in lucid dreaming, and so flying, passing through walls or telekinesis may not be possible in even the deepest lucid dreaming. It has also been suggested that looking at a clock twice in a row may help a practitioner determine whether or not lucid dreaming is intact; allegedly, the clock will display a different time each time it is observed. Here again, the clock’s display may not change in lucid dreaming.
One of the most undeservedly popular reality checks consists of trying to breathe out through a pinched nose. If you are able to do so, consider yourself in lucid dreaming. However, if there is serious doubt regarding the nature of the space you are in, this method may yield a false positive over one-third of the time. That is, you may be unable to breathe out through a pinched nose even when in lucid dreaming.
Of all the auxiliary procedures, one deserves mention and works in the majority of cases: searching for inconsistencies with reality in the surroundings. Although the usual surroundings of a practitioner may be 100% accurately simulated in lucid dreaming, it is very rare. Therefore, it is possible to figure out whether a lucid dream is intact by carefully examining the room where everything is taking place. In lucid dreaming, there will be something extra or something will be missing; the time of day or even the season will be inconsistent with reality, and so on. For example, when verifying whether a foul occurred, a room may be missing the table supporting a television set, or the table may be there, but be a different color.
There is also a quite logical method for determining whether or not a practitioner is in lucid dreaming. If an experienced practitioner experiences doubt as to whether lucid dreaming has really ended, then that one doubt is nearly always sufficient to conclude that everything around is still lucid dreaming.