After considering picking up another spell for a Wizard character I started comparing Bolt and Chain Attack in WFRP 4e.
Bolt is the default go-to spell for inflicting single target damage to an opponent. It is simple, relatively low CN (being CN 4), and as an Arcane spell gains all the great aspects of the Wizard’s chosen lore/wind.
Chain Attack is complicated. On first read I did not follow its strengths at all, and after pondering for a little while I’ve decided that Chain Attack is a thematic choice, and represents a less optimal choice from a purely mechanical perspective.
I didn’t understand why anyone would learn Chain Attack – especially when each extra spell is going to cost the character XP, and it has a huge element of risk in it (meaning I’ve read forums discussing that the additional targets are random – big assumption, wording isn’t clear). Given that Bolt can also use overcasting to strike additional foes, and that the caster can pick who they strike instead of it being random; it seems a terrible spell choice.
Then take off the spell mechanics hat, and consider the setting. It is amazingly thematic for Lore of Heavens though. Meaning specifically, I can’t think of a better spell to express how dangerous a lightning charge should be, and in hindsight (and support from a group of players) perhaps I should have taken up Chain Attack to really lean into how dangerous magic is supposed to be. Not so dangerous for the Wizard though; but terribly risky for their allies in close range to the nasty monsters.
I could see Chain Attack being renamed Caress of Shadow, or Cascade of Flames, or somesuch for each Lore and feel while it is a poor general choice it would be situationally bloody great.
Chain Attack = Same damage as Bolt, higher CN to cast (4 vs 6), a low probability to strike an additional target, and no control of who the additional targets are.
If you are designing a nasty NPC Wizard then the choice is clear … Chain Attack every time!