Greetings! Something's been bothering me for a while. There are some Tech cards with text like Plasma Cannon:

Tech - Commander

Resolution Phase

Place 1 Interceptor here >

Place 1 sucess on an enemy that has a soldier assigned to it.

Limit twice per round.

The rules state that cards whit the Resolution Phase icon can be used at "any time during Resolution". Does that mean that the Commander can use the Plasma Cannon right before the Squad Leader rolling against an Enemy Task? And, considering that as true, if the Enemy have only 1 Hit Point, what happens after? The Commander still rolls the XCOM/Alien dice, or the Enemy dies and we can ignore the dice roll?

I think that it would be less bothersome if Plasma Cannon is being used right after Resolution Phase begins (considering the same example above, 1 Hit Point Enemy with a Soldier assigned), since it wouldn't conflict with the task rolls. But if, by any chance, the card is being used right before the dice rolls, what happens?

Same logic apllying to other similar cards, like Light Plasma Rifle, Stealth Satellite (considering that only one UFO is on orbit in that case) and the like.

Soldiers aren't assigned to enemies until just before rolling against them, so the first opportunity the Commander has to use the Plasma Cannon is between soldiers being assigned and dice being rolled.

There is an entry in the in-app FAQ which makes it clear that there is a timing window there when you can add successes to enemies between soldiers being assigned and rolling the dice -

Q: If the Squad Leader kills an enemy using the Light Plasma Rifle, Blaster Launcher, Alloy Cannon, or Plasma Sniper before rolling dice, does the threat increase?

A: No. Threat only increases if a player actually rolls dice.

In general, you can use Techs immediately before rolling the dice, or between rolling the dice and applying the results, and there are some cases where the Techs are still relevant even after applying the results of a roll - like Alien Construction, which can be used to add a Success to Research I after waiting to find out how Research III goes.

In general, you can't use Techs/Assets before resolving Crises (in particular, you can't use the Laboratory before resolving the "discard all salvage" Crisis) nor after reaching the Refresh step (for example, having failed to achieve any successes in researching Elerium, you can't use Alien Construction once to add a success, refresh it during the refresh step, then use it again to add the second success and complete the research before moving on the the next step and returning the (probably exhausted) scientists assigned to that research, then play the following round with Alien Construction already exhausted, but get the extra Emergency Funding from having Elerium available during that Timed Phase) but you can at any time from when the Chief Scientist picks up the dice to when the Squad Leader finishes his attempts on the (Final) Mission.

Many thanks. The FAQ's entry was the key to undertand. The Plasma cannon kills the Enemy (considering a 1 HP alien), no dice rolls are done.