Recently I lost to an FM in 28 moves due to lack of opening knowledge. Can someone help me out and summarize the general principles to follow in unfamiliar openings? Please make it easy to memorize.
Your four main goals in the opening are:
Develop your pieces : playing (only once, and toward the center, if possible) each knight, bishop, central pawn, queen, and later rook.
Control the center
Put your king to safety ; most often, by castling
Annoy your opponent : as much as possible, prevent them to do the same and to reach a comfortable position; this requires carefulness about their options and tactical alertness.
I like Evergalo's answer, although I would modify it a bit.
- Develop your pieces. No one could disagree with this. But not necessarily toward the center. Fianchettoed bishops can be very good. Rooks, since they start on the edge, always move toward the center (at least on their first move) but the key for rooks is not center vs. not, but open file vs semi-open vs. closed. And which pawns should move isn't absolute, just look at hypermodern openings.
and I would add "connect your rooks" which will involve a queen move.
I do like the last bullet about "annoy the opponent" -- that one doesn't get mentioned so much.
Also, if you lost to an FM in 28 moves, it may well not be because of opening knowledge. I don't know your rating so excuse me if I am way off, but if you are asking this question, you probably aren't close to FM strength and 28 moves is a pretty long game.
I think @Evergalo's answer is 100% the best due to its conciseness. For those seeking a bit more detail...
10 Opening Principles from A First Book of Morphy by Frisco Del Rosario:
- Open with a center pawn.
- Develop with threats.
- Develop Knights before Bishops.
- Don't move the same piece twice if you can help it.
- Make as few pawn moves as possible.
- Don't bring your Queen out too early.
- Castle as soon as possible, preferably on the kingside.
- Play to get control of the center.
- Try to maintain at least one pawn in the center.
- Don't sacrifice without a clear and adequate reason.
Also very relevant is this answer: just play good chess.