This is the Real Assault Missiles Thread because most other discussion on this forum about the card has been limited to anecdotes, baseless speculation and whining.
There are thousands of ways unfocused Assault Missiles (AM) can roll against an unfocused/evaded TIE (when treating crits as normal hits and understanding that thousands of combinations have the same numerical value). The number of combinations becomes astronomical when taking to account modifiers and bonuses. Rolling a few physical dice means nothing.
First, lets take a look at how AM rolls without taking into account defense dice:
The top row shows how AM was rolled. 4 is AM with no modifiers. 4t/f is AM with target lock or focus (they are the same when treating crits as hits). 4H is AM being shot from Han Solo and rerolling when the first result is less than 2 hits. Finally, 4Hf is AM being shot by Han with a focus and rerolling when the first result is less than 3 hits/focuses. The left column shows the possible number of hits and the other columns show the respective chances of rolling that number of hits.
This information is somewhat useful but what we really want to know is how AM does against defense dice and more importantly, the chances of landing any sort of hit to trigger AM's splash damage.
For that, I made this chart:
Here, the attacks are in the left column, the defense dice are at the top (e is evade, f is focus), and the numbers in the columns are the chances of landing a hit. Han rerolls his dice when getting less than 2 hits without a focus and less than 3 hits with a focus. These are currently all the combinations except for ones involving other pilots' abilities.
To make it easier to decipher at a glance, here is a graph:
As we can see, focusing greatly improves the chance to hit and shooting into any ship that has focused and/or evaded greatly reduces the chance to hit. Not putting AM on the highest skill pilot might be a good idea. If higher skill pilots can strip away focus and evade tokens, that will greatly increase the chances of a hit.
Is the base attack of Assault Missiles particularly powerful? No, not really. Assault Missiles does less base damage than any other missile or torpedo currently. It isn't even much more powerful than a primary weapon attack especially when taking into account the target lock required.
Is Assault Missiles worth taking against TIE swarms? Definitely. Even if the base attack isn't any more powerful than a primary weapon attack, catching at least 2 other ships in the explosion will more than pay for the cost of the missiles.
Is Assault Missiles worth taking against non-swarm lists? I'm not sure about that. Against Imperials, the chances to hit won't be that great and it may be difficult to line up a decent shot on a group of ships. It would be worth shooting one at a Firespray if there are any other ships nearby. Against the rebels, the base attack is generally much easier to land but they have much more hull and shields, ways of regenerating them, and fewer ships usually. I think I'd rather take concussion missiles or spend the squad points elsewhere.