Q: What would constitute as a "tournament size" chess set?
Steve Schwartz
First of all, it is important to distinguish between what chess sets a tournament player HAS to take to a tournament and what the average citizen can play on informally. Most players don’t need to play with the typical tournament chess board size other standard size chess boards are fine for the average player. Indeed, many casual players are surprised by how large tournament chess boards are.
Many will go with a 15 - 18" chess board with chess pieces that have a 3" king. It is large enough to play chess comfortably and can fit on most coffee or side tables!
There are no rules or regulations for the 99.999999999% of the population that happens to play chess. But the tournament player is a bit more restricted by the rules. And the rules pretty much dictate that the chess board have 2 ¼" squares, and the king from the set of chess pieces be between 3 ¾" and 4 ¼".
In fact, the vast majority of tournament players use plastic chess pieces and roll-up vinyl or "mousepad" chess boards. These are quite inexpensive (even the most expensive of them).