So I've been thinking of a character concept and part of it would consist of him using demolitions. My question is what skill/characteristic is used for demolitions?

For demolitions, I'd probably point first toward Engineer - Saboteur. They have talents toward controlling blasts and detonations as well as being able to spend Destiny points to get out of a blast radius.

They're probably closest to what I'm assuming you mean by a demolitions character.

But what skill would placing a demo charge come under as far as rolling against a skill.

I'm being a bit lazy in not getting out the books, but I believe it'd be most likely to fall under mechanics, or possibly skullduggery if it's some sort of hidden type explosive.

Other than that, I am not sure that computers would apply to it, maybe in some rarer instances.

Mechanics is the skill used with explosives. Dangerous Covenants (the Hired Gun career book for the EotE line) has more rules on explosives and an actual Demolitionist spec. I imagine the same spec may make it into a Soldier career book once released.

Thanks guys I was guessing it would be tied in with mechanics just wanted to confirm. I wouldn't be surprised if they added a demolitionist spec for soldiers later on.

The Engineer: Saboteur has pretty much everything that the Hired Gun: Demolitionist has so I don't think they need another spec.

Just remember that since not everything is detailed in the books you and your GM will have to make rules as you place bombs. For example how many charges are needed to destroy a blastdoor? A house? A bridge's pylon?

Even on a smaller scale there are problems (as our last game showed) - according to the rules a single detonite cube cannot even scratch an ATST (those 'narrative' scale rules, I'm looking at you!). But in our game it was a dramatic dash of a droid character to place them on the machine, so it exploded.

In the game I ran for a while, there was a character who was hevily invested in the Demolitionist tree. He had both of the Improvised Detonation talents but never used them as written. Whenever he wanted to blow something up, such as a building or parked speeders, starships, or other vehicles, we just had him roll a mechanics against an arbitray difficulty. Then I'd narriate the results based upon how the dice pop up. Sometimes failure is failure to damage, sometimes it is failure to detonate. Sometimes success blows up the target, sometimes he needed several successes to get the wanted effects. Such as, one success blows a hole in a building but five would blow it up.

As Skie pointed out, as written detonite cannot scratch an ATST. That is where the Mechanics roll comes in. If you just throw a stick of detonite at an ATST, the explosion will not damage the armor. If you take your time and set the detonite on weak points, such as arm/leg joints, while the thing is sitting in the mortor pool, then that single stick of detonite can do some real damage. The Mechanics roll is the know how on where to put the demolitions for maximum effect when you have the time.

It's why in real life a building can be destroyed with a handful of explosives when placed by experts but you'd need several thousands of pounds of bombs to level the same building from air raids. It's all about knowing where to place the explosives to let physics assist in the destruction, such as taking out the correct support columns or attacking vehicle week points.

If you take your time and set the detonite on weak points, such as arm/leg joints, while the thing is sitting in the mortor pool, then that single stick of detonite can do some real damage. The Mechanics roll is the know how on where to put the demolitions for maximum effect when you have the time.

Unfortunately that's not true. A single stick of detonite does 15 damage, each more adds 10 more. You need at least 3, plus successes (and beating diff 3) to overcome ATST's armour... And there is 15 (!) HT, which translates to 150 (!!!) WT in personal scale... This whole issue begins to look like farcical - imagine this poor ATST with detonite sticks everwhere on it

Baradium seems to be perfect for the task (since it does vehicle scale damage) but it is described as extremely volatile - not a good option for combat actions.

So like you I'll just wing it and just assume that two well placed detonite charges (the player rolled 8 successes too) can wreck an ATST... After all two wooden logs could!

Yeah that's definitely one of those cases where you have to take things more narratively than mechanically. I take the damage of explosives as what they'll do to PCs or important NPCs if they're in the area, otherwise it's all about where they're placed and how they do on the Mechanics check.

Agreed. Mines are designed mechanically to destroy vehicles, but beyond that I'd treat a sabotage attempt like any other check: set a reasonable difficulty and roll dice.

In the game I ran for a while, there was a character who was hevily invested in the Demolitionist tree. He had both of the Improvised

It's why in real life a building can be destroyed with a handful of explosives when placed by experts but you'd need several thousands of pounds of bombs to level the same building from air raids. It's all about knowing where to place the explosives to let physics assist in the destruction, such as taking out the correct support columns or attacking vehicle week points.

Actually, it takes about the same amount of explosive. The difference is in the timing and dispersal of the explosives when bringing down a building. For example, the OK City bombing used about 7000lbs of explosives and would have brought down the building with slightly better placement and prep. That same amount of explosive would have been placed at various strategic places in the building and connected to timers to control how the building comes down. Take a look at most photos of explosives placement in imploded buildings and you'll see columns just wrapped up with detonite.

Kallabecca, if that same 7000lbs worth of explosives would've been placed by demolition experts in strategic places, then the whole building would've come down, not just turning the front/middle into a crater, and there would've been reduced damage to surrounding buildings. That is the advantage of blowing up support columns and letting gravity do the work as opposed to just trying to vaporize a chunk of it.

And yes, RAW is strictly damage applied to soak/armor and WT/HT. With RAW, all that a Mechanics check will get you is the ability to add more sticks of explosive for a bigger boom. There are no rules for trying to exploit a weak spot. As written, there is no way for Luke to cut open the bottom of an AT-AT and chuck a Thermal Detenator in there, as he did in ESB. A lightsaber is only 10 damage and breach 1 while a TD is only 20 damage and breach 1. There is no way either of those would scratch the armor. What I'm suggesting is that a GM handles explosives narritively. If a demolitionist player has time to sabotage an AT-AT and they have the proper supplies, let them. Come up with some difficulty and narriate the outcome. A weak spot, such as joints, can be damaged with well placed explosions and could render the vehicle inoperable (effectively destroyed) for the scene. You could also follow the Aim rules, which allow you to shoot someone in the leg to slow them for a scene, and apply it to demolitions. You could also be allowed to pick a desired result off the crit chart or just roll on the chart.

All that I'm suggesting is that if a demolitionist player wants to sabotage with explosives or conduct controlled demolitions, that the GM should work with the player to come up with whatever dice rolles and narritive is needed to accomplish the task and maintain fun at the table. I feel that as written, there are a lot of holes in the expanded explosives rules.

If the character was aiming for a weak spot, I would make them roll (they need to know where the best weak spot is) UNLESS they state where they are planting the explosives, then a Mechanics check to plant the explosives, then roll for a crit with a boost depending on where they planted the explosives