If two seismic charges go off and destroy the same obstacle, do you deal out two damage or one?

Only one of them has an obstacle to destroy. It's gone when the second one goes off, so you have to choose another obstacle or it does nothing.

But they detonate simultaneously not one after the other.

Nothing in x wing happens simultaneously.

I hear what you are saying

Here is a similar problem

After some nifty flying I get to drop two proximity’s touching the same two ships. Do I resolve one detonation and deal all damage then resolve the next one. Which seams a bit unfair as I can then see if I kill the first ship, before allocating the second device.

• If a device that detonates when overlapped is placed under more than one ship’s base, it detonates instantly and the player placing the device chooses which ship it affects.

And going back to the original question

I don’t see any immediately or anything saying it’s one bomb first then the next!

But it does say each ship get one damage, so two charges = one damage if you target the same object

At the end of the Activation Phase, this device detonates.
When this device detonates, choose 1 obstacle at range 0–1. Each ship at range 0–1 of the obstacle suffers 1 󲁧 damage. Then remove that obstacle.

6 minutes ago, Andyjp said:

And going back to the original question

I don’t see any immediately or anything saying it’s one bomb first then the next!

But it does say each ship get one damage, so two charges = one damage if you target the same object

At the end of the Activation Phase, this device detonates.
When this device detonates, choose 1 obstacle at range 0–1. Each ship at range 0–1 of the obstacle suffers 1 󲁧 damage. Then remove that obstacle.

1

The devices will go off in the player initiative order, with all "tied" ones resolved up to taste of each player from among all their devices. They all share a single "trigger" but resolve in series, simply because nothing happens in parallel in this game. See Rules Reference, page 2 - Glossary - Abilities - point 3.

So, after applying the rules of the Ability Queue the Seismic Charge #1 detonates, it's owner chooses an obstacle in range of explosion to remove, ships in the range are assigned damage and then the obstacle is removed. Now that Seismic Charge #2 detonates, there should be 5 obstacles left on the board to choose from, limited by range.

Good news is, if you detonate two Seismic Charges using different obstacle with each, you can deal two damage per ship provided the ship is at range 1 of both obstacles.

47 minutes ago, Andyjp said:

Here is a similar problem

After some nifty flying I get to drop two proximity’s touching the same two ships. Do I resolve one detonation and deal all damage then resolve the next one. Which seams a bit unfair as I can then see if I kill the first ship, before allocating the second device.

• If a device that detonates when overlapped is placed under more than one ship’s base, it detonates instantly and the player placing the device chooses which ship it affects.

Well, since the two devices must have been dropped by two different ships, and only one ship can be active at a time, even in the System Phase, there's no other way to resolve this.

Bomber A drops a prox mine, which overlaps two ships. It immediately detonates and you choose which ship is effected. Then Bomber B activates and drops a prox mine... etc.

Also:

Triggered effects use the ability queue, so they must resolve one at a time.

Got it on both counts now.

Thanks for the replies

🙂