I know FFG has divided adversaries into broad categories but even a casual glance will tell you that not all Rivals, for example, are created equal.

Is there a way to rate adversaries within the various categories to create a balanced encounter? Eg: these rivals are good for a party with 100xp while -those- rivals should be saved for a party with 400 xp.

Not really, every party is different too, some 4 character groups may only have a single combatant who focused on melee, another group could all be master Assassins with skills at ranged and melee. The two groups require completely different adversaries.

The best things to compare are the NPC’s primary skills with those same skills (or the opposing skills) of the PC’s. Then have a little think about the soak/Wounds of the NPC, will it survive one hit from a pc? Many hits?

Then finally remind yourself that the characters don’t get xp for eliminating threats, just bring in reinforcements if the encounter is too easy.

And of course, the weapon/attack profile of the adversary can make a huge difference.

Definitely some things to think about. I'm still hoping to find a way to make the process more of a science and less of an art but that might just take experience.

If you are familiar with Ogg Dude’s Star Wars NPC generator, you can find an approximate power level for NPCs, however there is no exact science to this.

One thing I'm looking for is simply: can the average preferred attack result of a combat-oriented PC damage the adversary? Assume base damage plus 1 for this. Because if nobody can punch through soak for at least a point of damage, they also can't crit, making a tough adversary even more difficult. That's not a showstopper if you provide them with some alternatives (ways to boost damage or reduce the soak, unattended rocket launchers, or just clear paths to skedaddle), but it's something to keep in mind.

I was looking at it in terms of a dagger wielding rogue fighting an ogre (let's skip past why he's actually doing so and assume there's a reason for it). Ogre has a soak of 7 per Terrinoth. Let's put the rogue at a Brawn of 3. His base damage is 5 with a normal dagger (+2). If he hits with minimum success, he adds 1, so "base plus 1" is 6. To even damage the ogre, he's gotta hit harder with 3 successes to do 8 damage, and can then crit. Even with the dagger giving a boost die for Accurate +1, it's going to be a very tough fight.

15 minutes ago, Dragonshadow said:

One thing I'm looking for is simply: can the average preferred attack result of a combat-oriented PC damage the adversary? Assume base damage plus 1 for this. Because if nobody can punch through soak for at least a point of damage, they also can't crit, making a tough adversary even more difficult. That's not a showstopper if you provide them with some alternatives (ways to boost damage or reduce the soak, unattended rocket launchers, or just clear paths to skedaddle), but it's something to keep in mind.

I was looking at it in terms of a dagger wielding rogue fighting an ogre (let's skip past why he's actually doing so and assume there's a reason for it). Ogre has a soak of 7 per Terrinoth. Let's put the rogue at a Brawn of 3. His base damage is 5 with a normal dagger (+2). If he hits with minimum success, he adds 1, so "base plus 1" is 6. To even damage the ogre, he's gotta hit harder with 3 successes to do 8 damage, and can then crit. Even with the dagger giving a boost die for Accurate +1, it's going to be a very tough fight.

Dont bring a dagger to a ogre fight ?

But in essence of what you are saying be ready to adjust or add some enviroment that can be used to help.

Or have a weapon with pierce.

In all likelihood they will have the Backstab talent, so only 2 success are needed as well. Then they should have pierce too, perhaps with an attachment on their dagger.

Or don’t be a rogue fighting an ogre on your own? Anything with Soak 5 or more is going to be a real challenge even for four pc’s let alone one lonely rogue