Fakery: High Resolution Fluid Sim I want to make an animation of an arrow (like from a bow and arrow) piercing a raindrop. Pretty quickly, it occurred to me that if I want to make a rain scene straight up, I would have to use a gigantic domain and extraordinary resolution. In addition to being probably not the best idea, I'm working on an 8-year-old computer which can't do that kind of hard core simulating.

What I'm asking is what is the best way to make a rain scene that can be interacted with? I'm fine with any sort of fakery as long as it looks decently realistic.
You definitely don't want to use a fluid simulation for rain. I'd use a particles system for the general rain in the scene. You can use Dynamic paint to make the particles interact with a "water" surface to make ripples (without actually using fluid sim).

For the arrow piercing a raindrop, that's more like a hero shot, up close in the foreground. I'd probably use soft body physics on the raindrop as it will be large in the shot (possibly), and at that size the surface tension of the water drop will be more like a gel object instead of flowing water (until it bursts). The trick is once the arrow pierces through and breaks the surface tension. At that point you do want something more like a fluid sim effect to show the displaced water splashing out around the arrow.

Here's a quick mockup of the fluid sim for the hero rain drop. Note I went for a slow motion look and decreased the gravity to -1m/s2.