In Axis and Allies, how many submarines do I need to have a greater than 60% chance to take down a lone aircraft carrier?
Check out the Axis & Allies Combat Simulator/Calculator. You can choose which variant of the game you're playing (Original, Revised Edition, etc.), how many simulations to run, and a number of other options. (There's even a iPhone and Android versions!) The combat simulator then tells you the average IPC loss for both sides and the average winning percentage.
Presuming you play with the Revised Edition (a/k/a, the 2nd Edition), here are the odds. (Note that each simulation has a link to the combat simulator with the attacking and defending units already entered. The link sets the simulation runs parameter to 1,000, but the results I present here were computed using 5,000 runs.)
- 1 sub: 49.8% chance of winning, average IPC loss: 4 for attacker, 8 for defender
- 2 subs: 85.4% chance of winning, average IPC loss: 4 for attacker, 14 for defender
- 3 subs: 97.9% chance of winning, average IPC loss: 2 for attacker, 16 for defender
What about super subs (which attack at a 3 instead of a 2)? If so, here are how the odds unfold:
- 1 supersub: 67.1% chance of winning, average IPC loss: 3 for attacker, 11 for defender
- 2 supersubs: 95.0% chance of winning, average IPC loss: 2 for attacker, 15 for defender
- 3 supersubs: 99.6% chance of winning, average IPC loss: 1 for attacker, 16 for defender
Also, because a sub has the benefit of "first attack," there will never be a scenario where both the sub and carrier are destroyed. In this type of battle you know that one side (and only one side) will be standing at the end.
So my precious calculations were simple, just to get a rough idea since you only wanted to know what was needed to get above 60%
Now more advanced calculations show (this is not exact, but close)
- 1 sub: less than 50% (around 48%)
- 2 subs: about 87.5%
- 3 subs: 98-100%
You can calculate it more precisely, but it won't make much sense though.