What is a NPC player exactly

Bots.

Alliance, Express and FFA all have a set number of countries that are bots ran by the admins to provide free land and market stability to players.

People have a few different methods for identifying them, but largely they are fantasy character names with proper capitalization (i.e. Salty Jacob Ravenbeard)

On express the NPCs are marked in yellow on the scores list which can help a lot in identifying them.

There are NPCs on express, alliance and FFA.

Non player country

Not to be the biggest nerd in the room but it means: nonplayer character.

Haha, learned something =)

Makes land grabbing easy

I find they always have wayyyy too many spies for me to even see what they have... or is just a plain old invasion the way to go, given the amount of land they have surely is taking a lot of their NW?