Good observation. Considering stacking of pieces maybe 1.5D though.

Chess has different pieces, which has higher entropy than a true 1d backgammon or 1d checkers with only one piece a field.

You could play with pieces that have a value of 1..N instead. Starting with 2,3, and 5 value pieces, and splitting them as needed. Making it one-dimensional again, while keeping 100% of the rules.

Final verdict, therefore: backgammon is 1D, not 1.5.

We could pretend that the second dimension was not playing a role in tactics back then, since it was very recently invented, like the brothers Wright invented the third dimension a hundred years ago. Or some hot air balloon at a world faire did it.

The "dimensions" in these board games isn't a mathematical/topology thing, is it? Normally one dimension = one real number space. Every board game ever would fit in 1D then, "2D" chess included.

I'm fine calling Backgammon 1.5-D. Physically you focus on a single dimension, and the second one matters too but it's not the same.

That's a good point, you could surely model full chess in a single dimension, it would just be that each pieces' movement rules would be more confusing

E.g. a pawn can move exactly 8 squares towards its opponents end (16 on its first move if no piece occupies 8 squares away), but can only capture 7 or 9 squares forward (with some extra modulo math to prevent wrapping)

Yeah and it'd be even worse if you want to flatten out the piece colors and types into the 1D array.

Backgammon, the game everyone's seen and at the same time nobody knows how to play :P

My brother and I once took a train trip from L.A. to Omaha and back for a friend’s wedding and played backgammon for most of the trip. For weeks afterwards, I saw backgammon everywhere (most notably when reading dialogue-heavy books with lots of 1-line paragraphs).

Solitaire and Hearts too. Well I actually know and love Hearts, but most people seem to know it as "that game in Windows where you play random cards"

You’d be surprised – take a Backgammon board to a table in at a cafe in a popular area and chances are someone will sit down to play with you. Can be a good way of meeting people in a new area. (or new people in an old area!)

It was a good way to while away the time at jury duty back in the days when you had to physically be there until you were called. I encountered a tournament player who beat me maybe 4 times out of 5. I also played in a chess tournament where my opponent was considerably stronger and faster and quickly put me in a position where I had to think long and hard to try to avoid disaster (fruitlessly in the end). She would make her move, wait a few seconds to see if I would reply, and then get up and disappear into a back room where, I found out later, she was playing backgammon. I looked her up and learned that she was a rapidly rising women's chess star but was better known as a semi-pro backgammon player.

I learned to play backgammon because it was one of the three games on my Nokia phone circa 2001 :P

There are tons of 1D games. Somebody else mentioned Mancala, and I'd also mention the venerable Game of Goose, which can become anything from Candyland to sophisticated things like Kramer and Kiesling's That's Life or Parlett's Hare & Tortoise. Hell, Monopoly is also 1D if we're willing to allow circuits like Mancala.

Goose/ Snakes and Ladders can be played with no human players at all. There is no interaction, just randomness.

Ludo/Parcheese could have been more played among Southern Europe/Latin American people.

Mancala is roughly 1D too!