How does FIFA divvy up teams? What I'm Learning: World Cup 2018

BLUE: Teams qualified for World Cup

GOLD: Teams failed to qualify for World Cup

BLACK: Teams expelled from the tournament by FIFA prior to playing a match

GRAY: Countries were not FIFA members

What teams get to attempt World Cup qualification?

As of this writing there are 211 national teams recognized by FIFA. Of these 211 teams, only 32 teams will ultimately make it into the 8 groups of 4 competing at the World Cup.

Over a two year period, tournaments are organized by the following confederations (based on region) to determine who will advance to the World Cup. Regions with more teams, and more higher ranking teams, get a greater number of spots. Notice in FIFA's rankings that Europe has more spots than other regions.

CAF - Africa (5)

CONCACAF - North America, Canada, Caribbean (3)

CONMEBOL - South America (5)

OFC - Oceania (0)

AFC - Asia (5)

UEFA - Europe (13 + 1)

Europe shows "13 + 1" because Russia automatically qualifies being the host nation. Detailed tables about the confederation qualification matches can be found here.

As a side note, future World Cup events will have more teams participating. More on that some other time.