Chess is harder than Backgammon because Backgammon has fewer moves and fewer rules. Since Backgammon involves dice rolls, it also has an element of luck so it is easier for a weaker player to beat a stronger one on any given day. Luck does not play a role in Chess so it is harder than Backgammon.

Is backgammon a difficult game to learn?

Very difficult to master. It's nice though, unlike most classics it works well between a novice and more experienced player still as the novice tends to still win sometimes unlike games like chess. It's best though played over say a 7-point series using the doubling cube.

Is backgammon a game of skill or chance?

Backgammon is a game of skill, and the more skill you have, the more likely you are to win. That is proven time and time again in tournaments and match results. But it is proven only in the long run. In the short run, just about anyone can beat anyone given enough luck, and when you have dice, you have luck.