An N scale train is a model train that is 160 times smaller than the real train it is replicating. Hobbyists uses them extensively in limited-size model train sets and in some war gaming layouts. Their small size makes them perfect for replicating large and complex railroads where the larger HO or O gauges would be impractical.
Variance - The standard for N scale is a ratio of 1:160, meaning the trains used on the 9mm (0.35 inch) track are 160 times smaller than their real world counterparts. However, variants on N scale exist around the world, with Japanese trains running at 1:150 scale and many British models being produced in 1:148 scale. Each uses the same 9mm track.
Significance - The small size of the models and rails themselves mean N scale is an excellent choice for creating model railroads in a limited amount of space. Because it is about half the size of the more common HO gauge, a model in N scale can contain more track in the same space, allowing a more complex model to be created.
Benefits - Because of its small size, N scale models are only slightly larger than the 1:144 scale used for many war games featuring miniatures. This allows N scale trains appropriate to the period to be features in a campaign, either as background detail or as part of the game itself.
Misconceptions - Because of problems creating reliable moving parts on such a small scale, N scale has gained a reputation for unreliability. However, modern production systems have allowed higher quality model parts to be created on N scale, meaning a modern layout is every bit as likely to function well as an HO gauge train.