Guild Wars 2

The tooltip for Arc Lightning says, that it affects 3 targets, but in my case it only hits one target … Is this the tooltip error or Scepter Air att. autoattack is bugged?

I think it means it hits up to 3 targets that go through the piercing beam.

nearlight.3064:

I think it means it hits up to 3 targets that go through the piercing beam.

Correct.

The same is true of Mesmer GS #1 and Scepter #3 beam skills - they’ll hit all foes that are between caster and target, but none behind them. You need to target a farther away enemy if you want it to hit multiple foes.

I think a couple of piercing arrows/bolts also behave like this, although most will just carry on along their trajectory after hitting targeted foe rather than stop like the beams.