Undefended projectile difficulty

In yesterday's game, an issue came up and I could not find the clear answer in the rules.

Character A shot an arrow at character B (so the arrow would deliver a tethered magic touch-range spell). Character B was not trying to dodge. What defines the difficulty of the bow shot roll?
Now let's add the next factor: Character B was being swept away by a torrent of water when character A shot him. How do you account for the increased difficulty?

IIRC, ArM4 had a rule for fixed ease factors for projectile weapons. Is there a similar thing in ArM5 that I just didn't find? I have access to core rules and Lords of Men for this kind of subject...

Okay, barely related question: Our PC tethered-magic hermetic archer wants to deliver touch-range spells through arrows, avoiding damage for friendly targets. She wants to use blunted/padded arrow tips (of the sort we see used nowadays in live-action roleplaying games...) How would you houserule the workings? I suggested that range increment was 12 rather than 15, that the changed balance would give -2 to attack rolls, and that only a botch would result in damage. Does that feel balanced?

Well, I would say not dodging at all is tantamount to botching a dodge. A botch on a dodge gives a defense of 0. So I would use that, in the absence of something else such as an illusion throwing off the archer. Still, the difficulty will rise with distance, and that is clearly defined.

I'm not sure about the second situation.

Chris

I'd agree with Callen about using 0 for a stationary target if your troupe wants something easy to apply, but I could also see a small penalty being based on size being applied: A barn door (classically easy to hit) could be eg an extra +3 to hit; each smaller size target could increase the base defense a bit. You also probably want a willing, stationary target being easier to hit than a person with zero quickness/dex taking avoiding action, and you could argue that even someone with negative stats but actively dodging should be harder to hit. Having tried a bit of archery, it is fairly easy for even untrained, averagely-statted people to hit size +1 stationary targets up to about 50 ft away - ie ease facter of 6.

Being swept away by a torrent of water should make it harder to hit them - that would depend on how fast the water was moving, and the target area is much smaller, being mostly just the bust (head/maybe shoulders). Size -2? or -3? Speed penalty - perhaps 3 for walking pace, 6 for running pace, etc.

Blunted/padded arrows: if only a botch does damage, what if the 'attack' isn't good enough to actually hit the target? (maybe roll again for that. Remember, a botch reduces the attack total to zero.) Or have the arrow maker roll for each arrow (when it is fired (technically 'loosed')), and only if that is a botch apply damage?
Your range/attack penalties seem OK for a blunted arrow (eg doing half damage, or limited to a light wound) but I think that a well-padded arrow will have bigger ones since it won't fly well at all.

Alright, so for a stationary target, ease factor (0 - size), modified by range increment, makes sense. I'm still unclear on how to rule for target movement/action though. ArM5 combat rules are streamlined--I see nothing about a surprised defender, or "shooting into a melee". Benefitting from a defense total without a die roll could make sense for a character engaged in a melee, but not actively defending against "friendly fire'. As for non-combat situations, I might as well go with the suggestion of arbitrarily adding +3 or +6 to ease factor for regular/slow and chaotic/fast movement, unless there are other suggestions?