In Agricola (Latin for "farmer"), you're a farmer in a wooden shack with your spouse and little else. On a turn, you get to take only two actions, one for you and one for the spouse, from all the possibilities you'll find on a farm: collecting clay, wood or stone; building fences; and so on. You might think about having kids in order to get more work accomplished, but first you need to expand your house. And what are you going to feed all the little rugrats?
Agricola is a turn-based game. There are 14 game turns plus 6 harvest phases (after turn 4, 7, 9, 11, 13, and 14). Each player starts with two playing tokens (farmer and wife) and thus can take two actions per turn. There are multiple options, and while the game progresses, you'll have more and more: first thing in a turn, a new action card is flipped over.
Problem: Each action can be taken just once per turn, so it's important to do some things with high preference. Each player also starts with a hand of 7 Occupation cards (of more than 160 total) and 7 Minor Improvement cards (of more than 140 total) that he may use during the game if they fit in his/her strategy. This amounts to countless strategies, some depending on your card hand. Sometimes it's a good choice to stay on course, sometimes you better react on what your opponents do.
Agricola can also be played without cards (family game) and can even be played solo.