During your stay at the Sword Coast you may encounter many different types of enemies and equally as many unique player characters.
The spawn system ensures that almost all creatures are randomized to a certain degree which means they can become bigger or smaller in size (also affecting their stats) or they might be exceptionally capable of spotting or listening for sneaking enemies.
The system is setup to ensure plausibility while also guaranteeing that almost no encounter is ever the same without gravely upsetting the Challenge rating of an area.
Many creatures that were custom made by the NWN2 community have been implemented to populate the server in environments suited to their ecology. The server currently has well over 350* areas to explore and many more are being added or retouched by the exceptional crew of area designers and builders that are part of the Baldurs Gate Community *cheer for them*. (* = old count)
An example of custom creatures are: Gibberlings, Hydra's, Giant serpents, Basilisks and the list goes on.
About the Spotter Script:
On the spotter script: The so called "spotter script" has been scaled back a lot since it's first appearance on the server to the point where almost 99% of the monsters you'll encounter won't have any edge added to them. Additionally it takes into account what plausible boost a creature could have and doesn't give true seeing to dogs or lions, for example. Be warned however that certain races such as Dragons possess True Seeing, rendering invisibility and etherealness a moot strategy. This includes Wyverns!
Special thanks to RWS and Bouncy Rock for their work on creating custom creature models for the NWN2 community!
System curtesy of Rasael and Ivan38Rus