Talk:Seismic Torpedo/@comment-80.57.63.23-20160805211829/@comment-454133-20160805224454

Good question... The three closest rules may be measuring before deciding to acquire a target lock, measuring before firing a weapon (say, primary weapon, assault missiles, etc), and choosing to boost/barrel roll.

The attack measurement happens when you're declaring your target, and you can measure freely and pick from among available ships. However, with this being an action, it's probably closer to other actions that have range or other restrictions.

When you want to get a target lock, you have to declare that's what you're doing, then measure. If the ship you intended to lock is not range, you choose another ship or another action. Things are similar with boost/barrel roll -- you have to declare the action before measuring, and you choose a different action if you can't complete the movement legally.

So I'd guess you must declare the Seismic Torpedo action before measuring. As you discard the card as part of performing the action, I'd say changing actions means you don't discard. If you measure and cannot perform the action, you probably get to switch to a different action.

A bit speculative and it could turn out differently, but if it's like other actions, you won't lose the card if it turns out you can't hit anything. Err... probably.