When it comes to setting up your board in Stratego, the position of your bombs should be a key consideration. Cleverly placed bombs can be devastating to an opponent by destroying their best pieces, or even guarantee you a victory if the opponent has no way to disarm them. Here are the general types of bomb placement options, and why you might want to use them.
1. Bombing the Flag
Pro: Bombing the flag is the term for surrounding your flag with bombs on all sides. Obviously, this takes fewer bombs in a corner than it does in the middle of your board, but generally speaking, bombs are the best defenders in the game, victorious against every piece except miners.
For this reason, it's obvious that putting your strongest defenders around your flag is a good play. As a bonus, if you manage to destroy all of your opponent's miners before the bombs next to your flag are defused, you have guaranteed that the opponent cannot capture your flag.
Con: Since bombing the flag is such a strong and obvious strategy, most players who run into a bomb (especially in a likely flag area like a corner) will immediately send stronger reinforcements to defuse the bomb and explore further. A bomb is like a bright neon sign that tells the opponent "I'm defending something valuable!"
Conclusion: Predictable though it may be, bombing the flag is definitely one of your strongest Stratego setup strategies. The defensive power of bombs is so strong that you should use them to guard your flag most of the time.
2. Decoy Flagposts
Pro: As mentioned above, bombs near a corner are likely to attract your opponent with reinforcements. For this reason, it's a common ploy to place bombs next to a corner with no flag in it. Your opponent's forward troops will die to the bomb, and then if and when reinforcements finally break through the bomb to the corner space, you may have another surprise waiting for your opponent. At the very least, the opponent will have wasted some time attacking an area that isn't your flag.
Con: Uses a few bombs in the back row that you might want for something else. If your opponent never reaches that corner, you've possibly missed an opportunity to explode some troops.
Conclusion: There's no real drawback to decoy flagposts, especially since your opponent can't walk away from what might be a flag. If you don't need the bombs elsewhere, a decoy flagpost in the corner is pretty much always a good idea.
3. Two Wave Corner
Pro: If bombs defending a flag are good, more bombs defending a flag are better! This strategy requires making two diagonal rows of bombs in front of your flag, with a layer of troops in between to kill any miners defusing the first row. In this diagram, F is your flag in the corner, B is your bombs, and X is your other troops:
The defensive power here is very strong. The first wave of bombs will likely kill a troop or two before a miner is sent in to fix it, at which point you can kill the miner. Your hope is that nobody makes it through the second wave of bombs.
Con: You're pretty much putting all of your eggs (or egg-shaped bombs) in one basket with this strategy. With no bombs anywhere else on your board, your opponent will likely figure out that heavy resistance likely means a flag nearby.
Conclusion: Worth trying occasionally. It's not very subtle, but if you can defend your bombs or kill the opponent's miners, this is a tough defensive wall to crack.
4. Bombs Forward
Pro: Putting five of your bombs in the front six spaces is going to kill some early opposing troops. (You can't put all six there, or you'd immediately lose the game for having no legal move.) If your opponent was playing aggressively and leading with powerful pieces, so much the better.
Additionally, if your opponent has buried the miners deep in the backfield, you'll have a long time before you have to worry about defense. With only one open lane into your troops, you can focus your power.
Con: If your opponent starts with a scout or two that explode when hitting a bomb, it may become clear what you are doing. Additionally, this strategy can backfire if your opponent decides not to defuse the bombs and your pieces end up trapped behind them.
Conclusion: Not a great strategy, even if it does make for a funny opening game.
5. Bombs One Row Back
Pro: This strategy is more popular with many Stratego players, as it allows you to more fully defend all six open columns. Placing a row of pieces in front of your six bombs blocking the open lines means you can still do a lot at the beginning of the game. Ideally, you'll be eliminating your opponent's weak pieces and miners, so that only powerful pieces can reach the second row to be destroyed by your bombs.
Con: Uses your bombs so you don't have them for flag protection or decoys.
Conclusion: If you're looking to try something a little different, this strategy can be highly effective.
Pro: Your opponent cannot outguess you if your bombs are placed randomly.
Con: Your bombs don't work towards a larger strategy if placed randomly.
Conclusion: Random placement is the last resort, only use against opponents who keep figuring you out.