Can you use Wasp Jump Packs in assault without charging?

My question is simple and pretty much in the topic - Corsair Wasps have the Jump Pack that allows them either an 8"-12" teleport during Movement at the cost of getting onto snap shots, or a highest 2-of-3D6 charge and bonus to HoW when used in Assault. If it uses either, the Wasp gets a rerollable 4++ until the next turn.

It's possible to abuse that by declaring a charge, using the Jump Pack, then using Fleet to reroll dice to make sure you don't make the charge and are a nice rerollable-4++ toting gun platform the next turn at the cost of eating some Overwatch. However, can you declare that you're using the Jump Pack during assault, but then not actually assault? This would give the rerollable 4++ without having to suffer overwatch, as well as allow you to use it after Scouting, out of Reserve, or in other situations in which you're not allowed to charge.

The text in IA11 is, "A Wasp jump pack can be used in either the Movement phase or Assault phase... If used in the Assault phase, the Wasp Assault Walker may roll an additional dice when determining Charge distances and use the two highest results, and additionally gains the Hammer of Wrath special rule for that phase, inflicting D6+1 hits instead of just one."

Seems to me that allows you to declare use of the pack without charging, though that's something I'd appreciate a second opinion on. And just as a side note - would Immobilization prevent the Wasp from using its Jump Pack too, or would that just cripple the "leg" parts of it?

Seems to me like a 70-pt Wasp toting a pair of Scatterlasers with a rerollable 4++ save that can also assault in a pinch wouldn't be an unwelcome addition to a force that includes Corsairs.

MHaruspex wrote:

If used in the Assault phase, the Wasp Assault Walker may roll an additional dice when determining Charge distances and use the two highest results, and additionally gains the Hammer of Wrath special rule for that phase, inflicting D6+1 hits instead of just one."

Seems to me that allows you to declare use of the pack without charging, though that's something I'd appreciate a second opinion on.

It seems pretty clear to me that you CANNOT use the pack in the assault phase without charging, as it's only effect is to add a dice to "charge distances", which ONLY come into play if you're charging. So, they're not actually able to make a jetpack/jump move in the assault phase at all, by that reading. It's only useful for assaulting in the assault phase.

Right, I agree that they can't make a jump move during assault. However, they do say that you use the jump pack during assault, which lets you roll the extra die when assaulting.

Question is whether you can activate it to get your bonus to charge distance but then not actually use it beyond that.

MHaruspex wrote:

Right, I agree that they can't make a jump move during assault. However, they do say that you use the jump pack during assault, which lets you roll the extra die when assaulting.

Question is whether you can activate it to get your bonus to charge distance but then not actually use it beyond that.

What is the point of that? I guess I don't understand what you're asking. What benefit is there to activating your pack to charge, then not charging?

Activating the pack in either phase gives you a 4++ save, as well as allowing you to reroll that save.

In that case, yes. It seems like you can choose to activate it in the assault phase and not assault if your posted wording is accurate, though I don't know the wording of the 4++ rule and don't have my book handy.