I am a beginner. With reference to opening theory, which opening should I start learning?
My friends are suggesting Ruy Lopez...
To answer your question directly, your friends aren't wrong, and it's not a bad idea at all for you to play the Ruy Lopez, from both the white side and the black side. In fact, knowing nothing much about you or your exact level of play, it's still a safe suggestion that opening with either
1. e4 or
1. d4 with white, and responding with
1. e4 e5 or
1. d4 d5 with black is a solid way to begin to get your footing in the opening phase of the game. Of course, that's just move one (and only the two most popular options for that), and there are plenty of forks in the road beyond that point. Nevertheless, while my advice to you is that playing the Ruy Lopez is a great idea, studying it (or any other opening) in any great depth is not, at least not right now.
Instead, you should focus on a few principles, like aiming to get your king safely castled in a timely manner, trying to control the center of the board with your pawns (our first moves above are a good start), and developing your pieces with the idea of using them to further control the center of the board. All of these ideas are visible in the Ruy Lopez, and that's one reason it is a good suggestion. After
1. e4 e5, we see that
2. Nf3 develops a kingside piece and helps control the central squares d4 and e5,
2. ... Nc6 fights for control of those same squares (and defends the e5 pawn), and
3. Bb5 indirectly fights for those same squares by threatening the c6 knight, while also clearing the path for the white king to castle. Part of my point is that all of these moves make a great deal of sense, just for the principled reasons given here, and can be recognized as such and played confidently without needing to get your hands dirty with a lot of opening theory.
To learn more about important opening principles, and what you should be thinking about in the opening phase of the game, you might consider checking out John Emms' book Discovering Chess Principles: Building Opening Skills from Basic Principles, which is aimed squarely at developing in beginners a good sense of how to make good moves in the opening. (You'll find good reader reviews at that link; for good measure, here's a review from Chessville as well.) In addition to that, I'd say what's most important is just to play a lot and have fun, keeping guiding principles in mind while you do, and when things do go wrong, make a point of determining why. Try to figure it out yourself, and any time you can't, seek out an explanation from someone else. (Maybe come back here and ask!)
I would recommend to start with the Accelerated Dragon for black (
1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 g6). It gives you a solid position and also has few nice traps at the beginning which work quite well for beginners. Then you could play the same moves with white and you will get a decent position (This could be called English opening or Reversed Sicilian). The important thing is that when you play it with white you play almost the same moves and 90 per cent of the time your pieces will be on the same position (e.g. pawns - c4, d3, g3; bishop - g2, knights - c3, f3; and so on ..) no matter what the black plays.
1.d4 I would recommend Slav, Semi-Slav or the Classical Queen's Gambit (
1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7). They are usually simple (compared to the things that could arise from
1.d4 Nf6 2.c4 g6) and solid defences.
If you face some weird starting move from white, then stick with the Dragon because, as I implied, it has very versatile possibilities.
For beginners I recommend one white opening and two black ones. The point here is that you'll memorize and learn enough to be effective without getting buried in a lot of pointless memorization. Learn a few openings, get to playing, then learn more, play more, etc.
About the openings, your choice depends upon what you're looking for in a game.
If you want games that tend to be open and attacking, as white
1. e4 is a great choice. The Ruy Lopez is the greatest of the e4 moves, and has about a million variations. For this reason you'll be unable to remember them all, and even if you did you wouldn't know what to do if your opponent made an 'out of book' move. For this reason, learn the purpose and philosophy of the openings. Then you can make intelligent, guided moves when you're 'out of your book.'
For black, learn 2 openings so you can respond to
1. d4 or
For the former, likely suspects for black include the Grunfeld or King's Indian (
1. d4 Nf6) or the Queen's Gambit.
For the latter, the French and Ruy are both passable.
If you like nothing more than a quick brutal game, learn the Sicilian
1. e4 c5. Be advised, you'll lose frequently until you get it down. If you're booked up and you understand the opening (can't stress that enough) you'll chop some heads.
All these openings are described in great depth in Wikipedia.
There's a good reason that beginners are coached to learn the Open Games (1.e4 e5) as both Black and White. These games are heavily populated with tactics that teach:
Because the central pawns are often exchanged or captured, or become reduced to a fixed ram pair, these games involve a lot of open lines, giving beginners a chance to learn to visualize long-range threats, and to combine line pieces to attack focal squares, such as by constructing batteries.
The density of threats and heavy bias towards tactics and away from strategy makes these types of games easier to understand for a beginner. Topics such as provoking and defending weaknesses (e.g. Isolated Queen's Pawns and doubled pawns), exploiting outposts, and endgame theory often involve too much complexity for beginners to be successful and enjoy the game.
Most beginners will remain more engaged and enjoy the game more if there is frequent capturing, it is easy to find active moves, and they can visualize what's going on easily. This is the same reason TD's are very lenient towards beginners; they want to avoid frustrating experiences that discourage play.
So, the traditional (and still useful) first openings include the:
and so on.
After some experience with these, beginners will be able to assimilate the new concepts required in the Semi-Open Games. The Sicilian Defense is a good candidate, for similar reasons, although it introduces the ideas of weaknesses, imbalances, stock sacrifices, queenside vs kingside play, and so on. Teachers advocate learning either the Caro-Kann or the French, after some experience with the Sicilian, to introduce more elements of closed positions and maneuvering.
Next, the Closed Games can be introduced, with their ideas of preparation of pawn breaks, center vs wing attacks, emphasis on weak pawns and outposts, and so on.
That's a rough outline of a fairly universally-applied sequence, with an explanation I've heard from several coaches.