The Vienna Game: Good, inferior or bad?

The Vienna is one of the better openings below international level. Objectively it's probably equal but that's true of nearly every opening. There's only a few openings that can even try to claim a small advantage nowadays (Ruy, Queen's gambit)

What I like about the Vienna:

1. it cuts off a lot of black responses like the Petrov, Philidor, Latvian etc.

2. It's very flexible. There are a lot of ways to play the Vienna. You can play the standard Frankenstein–Dracula Variation or you can transpose to a four knights or you can play something like the Bishop's opening or you can look to transpose into a king's gambit or you can play a very system-like approach with Bc4, d3, f4, Nf3 etc. The Vienna gambit with an early f4 is also surprisingly sound.

3. It's somewhat unusual meaning most black players won't as prepared as they should be.

4. It narrows your opening rep. Aside from what I said in #1 you can play 2. Nc3 as an answer to 1...Nf6. Black's best reply is 2...e5 transposing to back to the vienna game main lines. You can also fall back on the Bc4, d3, f4, Nf3 formation if black throws something at you you don't know how to play. With black you can play the dutch and reach the same positions if white doesn't prevent e5.

It's great until you reach 2000. After that don't use it as a main repertoire. The main repertoire should be the main lines. Then along the way you can get creative.

Knowing why the main lines are in fact the best will greatly improve your play after 2000

Hope this short but sweet answer helps!

At top level, the Vienna is certainly inferior. You can try checking the cloud analysis at Lichess. The position after 1.e4 e5 is about +0.3 in favor of White, but the position after 1.e4 e5 2.Nc3 is 0.0. In words, this means the Vienna is not as good as 2.Nf3 at fighting for an opening advantage.

However, if you aren't playing at top level (I doubt you are, simply because almost everyone on the planet isn't), then the Vienna is certainly viable. "Winning" in the opening is mostly a matter of reaching a playable position one is familiar with while the opponent isn't. At club level you can certainly expect opponents to know a lot more about 1.e4 e5 2.Nf3 Nc6 than they do about the Vienna. In fact it's entirely possible that your opponent is out of book after 1.e4 e5 2.Nc3 Nf6 3.f4. This move flips Stockfish's eval to negative, but if opponent has never seen this position before, will they even know that 3...d5 is the only move that doesn't lead to an advantage for White? I doubt it. They could very well react with 3...exf4 (after which 4. e5 Qe7 5. Qe2 forces Black to play 5...Ng8) or something even worse like 3...Nc6 (after which 4.fxe5 Nxe5 5. d4 pushes Black off the board). Wikipedia says as much:

However, lines other than 3...d5 give White at least an edge, making this a good choice for aggressive play at lower levels, where opponents are unlikely to know that 3...d5 is best.

Of course if you keep playing against the same people they will quickly learn the nuances of the opening, and an opening edge becomes harder and harder to find. But until they develop as good a grasp of the Vienna as you, you will likely continue to score easy wins.

Viewed the above way, the Vienna is a great opening because it's easy to get. If you play 1.e4 there's a very good chance the opponent responds with 1...e5. This is in contrast to, say, the Scandinavian where you might prepare a line but never get the chance to use it.

Summary:

1. Against an opponent as booked up as you, don't play the Vienna.
2. Against everyone else, feel free!

After 1.e4 e5 2.Nc3 Nf6 3.f4, White has definitely a playable position, but it's not that "strong". Indeed, this is the main line and Black should be about equal with correct play. Other lines will most likely tranpose into other 1.e4 e5 positions (say 2...Nc6 3.Nf3 Nf6)

So yes, the Vienna opening is indeed a playable one, probably not "the best", but the difference is not big enough to refuse to play it except maybe at the highest levels of play (if you are rated 2500 or below, you can play it with no problems, and indeed it can be a dangerous, surprising weapon)