What differentiates these two bomb types from the others is that these two aren't really thrown, but instead start at the alchemist and extend. They both state that one creature in the area of effect should be the designated target. If you hit, everyone in the area takes splash damage and none take direct hit damage, I think.
But what happens if you miss? It's fairly simple with thrown bombs which work with Throw Splash Weapon. But that doesn't apply to these two since there is no notion of range increments or a square where you throw the bomb.
So, how does it miss? Does a miss imply that you don't shoot out a cone or line at all, so nobody gets damaged? Or does just the target not get damaged, but everyone else still does? Or is your line or cone just slightly off and you actually attack other squares, similarly to Throw Splash Weapon?
I couldn't find anything about that in the combat or magic rules, but I'm fairly certain that there must be something there. The closest I could find were rules about aiming spells, but spells don't really "miss", they just give saving throws.
Benefit: The alchemist can throw bombs that splash in a 40-foot line rather than affecting a radius. The line starts at the alchemist and extends away from him in the direction he chooses. The alchemist designates one creature in the squares affected by the line to be the target of the bomb and makes his attack roll against that creature; all other squares in the line take splash damage.
If you miss, then the primary target would still be subject to the splash damage (and a saving throw for half.) The shape of the line doesn't change as a result of a miss; it is fixed when you apply the bomb shape. The same applies to the grenadier's directed blast.
That said, I'm not a big fan of strafe bomb, personally. It reduces the number of affected squares to 8 (in addition to limiting the range.)
Directed blast, on the other hand, is quite nice. Not only is it just terribly useful, it actually *increases* the number of squares your bombs affect to 13 or 14 depending on whether you aim it from a corner or not.
Of course, either of these bomb shapes can still benefit from Precise Bombs, making them even safer to use around the party.
If you miss, then the primary target would still be subject to the splash damage (and a saving throw for half.) The shape of the line doesn't change as a result of a miss; it is fixed when you apply the bomb shape. The same applies to the grenadier's directed blast.
So, that line about designating a target is completely pointless? You do the same damage whether you hit or miss?
Or do you actually do the full direct-hit bomb damage to the designated target if you hit? If that's the case, wow, that's ridiculously good and much safer than simply throwing a bomb.
Yep, if you hit the primary target, you do full damage to that target just like you would have done had you thrown the bomb.
Yes, it's quite a bit safer (though suffers from its own limitations), which is why it costs you a discovery (or an archetype.)
:) Happy bombing!
Yes, the target takes the full damage of the bomb if hit, just as with normal radial bombs.
As for the application of the discovery... enemies are not always so kind as to group up nicely so you can blast them with a radial bomb, but it's often easy to maneuver around to find the right vantage point for a strafe bomb or directed bomb that hits the targets you want and none of the ones you don't.