Detect causes almost all moves directed against the using pokemon during the same round to miss. Moves that target only the using pokemon (such as stat changers or Conversion) or do not target either pokemon (such as Weather moves or Spikes) will not be affected by Detect. There are also other moves which one might think would be stopped by Detect which are not. These include: Future Sight, Mirror Move, Perish Song, Psych Up, and Transform. In the case of Mirror Move, if Detect goes first (because it was used normally), Mirror Move will perform Detect, which will subsequently fail.
Detect is a protection move.
Protection moves are put in the same category because of a couple of reasons. The first is that they do as named and somehow protect the using pokemon. They also do not work when used with Substitute. The most important distinction about the group of moves as a whole is that the accuracy of the moves decrease when used consecutively, this includes using a different protection move consecutively. The accuracy decrease percentage scale is as follows (starting with the first use):
99.6 -> 49.6 -> 24.6 -> 12.1 -> 5.9 -> 2.7 -> 1.2 -> 0.4
Protection moves also have a higher priority for determining which pokemon goes first than attack first moves. The using pokemon will go before any pokemon not using a protection move. If an opposing pokemon also uses a protection move, then the one with the higher Speed will go first, as per usual.
Protection moves will automatically fail if they are performed as anything other than the first action in a round. The instances where this could happen include when a pokemon switches out, a faster pokemon uses a protection move, or if a protection move is brought up by either Metronome or Sleep Talk.
Since protection moves affect only the using pokemon, they are not subject to the effects of Accuracy/Evade modifiers such as Sand Attack or Double Team.
Protection moves include: Detect, Endure, Protect.
