Hey guys, ran an intro session explaining fate and doing character creation last week, and after looking at the characters I've got before me, I'm not sure about how much they can handle in the way of oponents.  They're a bunch of good characters, it's just that almost everyone's inexperienced in fate, and went the generalist route, so I've only got one character who's actually meant to handle a fight.

Going by the rule on YS336 to build bad guys by adding up all the points spent on powers and subtracting points spent on stunts for a mixed group; the bad guys for my players are all supposed to have negative refresh.   

Tanking out:
Bulletproof armor is usually behind guns because it faces a very real limitation; it has to be light. The average human can't wear armor heavier than fifty pounds and hope to retain any agility. Now, if you have someone super-strong who has no problem carrying around five thousand pounds...
What armor rating would you give to quarter-inch-thick hardened steel? That kind of armor for a human-sized combatant would weigh 200 pounds or so.

Given modern firearms to attack it with, a quarter inch of steel isn't bulletproof and is barely bullet resistant.  A modern .308 rifle could penetrate that to a couple hundred yards, modern military ammo (like Soviet or Chinese ammo with mild steel cores to cut costs) can penetrate a quarter inch of steel at 500 yards.  Modern armor piercing ammo could penetrate half an inch of steel armor plate at 300 yards and a quarter inch at double or triple that.  A .50 BMG rifle, which is sure to be dragged out if armored trolls are on the offense, can easily penetrate an inch of steel plate at 200 yards with standard ammo.

What about the same armor from various superalloys?

In generate these alloys aren't used as armor because when a plate gets too rigid it shatters much easier, other much denser alloys are often softer than steel, like depleted Uranium.  In general you don't end up saving a whole lot of weight, it just ends up thinner for the same protection.  But at this point you're talking about 3/4 of a ton on a man sized suit to keep out anything smaller than a .50 BMG rifle with Armor Piercing ammunition.

It wouldn't be any thicker thus bulk would be no problem but it would weigh a bit over five hundred pounds and its strength would be three-five times that of steel. Still, five hundred pounds are nothing for someone with inhuman strength and some might or supernatural strength and no might.
And now think of a troll with comparable quality and quantity of armor.

The other problem is that weight grows exponentially with size.  Double the size and you need eight times as much armor for the same protection; a 12' troll is going to need 6 tons of armor to keep out .50 rifle rounds and at that point someone's just going to treat it as the fae equivalent of a tank and hit it with a rocket.  Or magic, how well do you think a troll can swim in quicksand while wearing 6 tons of metal armor?

Size does matter:
With a multi-barrel 112 inches long, total length of 19 ft and a total weigh close to 600 pounds, the GAU-8/A is a BFG. It fires 30mm antitank bullets at a rate of 70 rounds per second and can turn tanks into swiss cheese. A superhumanly strong guy or gal that is still human-sized might have some trouble with its bulk but not its weight and a troll or ogre would wield it like we do an assault rifle. Since we have seen Gruffs use machineguns already, why not inhumanly strong opponents with that kind of heavy weaponry? They even have glamours that can hide their size and form until it's too late.
So, what weapon rating would you give the GAU-8/A ?

The GAU-8 is a tad more than 600 pounds.  Fully assembled it weighs just over 4,000 pounds with ammunition and that's without a power supply to rotate the barrels.  It's also a tad unwieldy, it's longer than a car and the ammo drum is about as big around as a volkswagen beetle.  You don't casually pick one up and swing it around without a plane sized mount for it.  For the same reason that if you could lift 50,000 tons you couldn't pick up a building and throw it - you'd just come away with two handfuls of concrete and the building would still be intact.

As for weapon rating?  The FATE system doesn't really model armor or damage above a personal scale, it just becomes a plot device at that point.  I've got better systems to use if a GAU-8 Avenger Cannon becomes a standard ranged weapon I need to stat out.

Also:

An A-10 Thunderbolt has to fire their guns in short bursts or the recoil will knock them out of the sky.

Complete myth I'm afraid, there isn't even enough recoil on that thing to even slow it down a few mph when it fires.  The reason it fires in short bursts is to avoid burning out the barrels through overheating.

Again, it's not an actual sword. It's a bar of fire. So it could conceivably block whatever a thick bar of magic fire could block i would think. Remember, a light saber is NOT a sword, and I'm trying to make a lightsaber. Not a sword. And a sword CAN block a bullet, it's the PERSON who can't do it. It's certainly possible for someone in this game to be able to intercept projectiles, even bullets. Likely? No. But we are talking about magic here.

  Per the books, magic doesn't work that way.  Let's say you cast a magic spell to make you super strong and you lift a car up over your head.  A fraction of a second later your are crushed because your bones and ligaments can't support a car.  You start swinging your sword around at 2,000 miles per hour and you'll rip your arms off.

Not to mention that a bar of fire hot enough to vaporize a bullet in 1/5000th of a second (the amount of time it would take a bullet to pass through it) is going to radiate enough heat to broil the wielder and set everything around him on fire.

Weapon 27?!  Surely, that's either a typo, referencing something else, or it is the god of all thrown hats!

In one scene the henchman, as a demonstration, used the hat to cleanly slice the head off a marble statue.

What about a mortal character that goes a sort of magical James Bond and has a huge store of magical items, but only uses them as needed?  So he may own -30 worth of items, but doesn't use them all at once. Then as the need arises he picks and chooses the ones he needs for particular missions, never using more than say... -7 worth at a time.

Is that within the rules?

That would be an absolute no per cannon.  Magic items run out of power if not kept charged, so you can't just keep piles of them lying around.  Making a caster and taking 7 levels of refinement would let you do it.  In another thread we've already taken a look at how strong a pure crafter could be in a game.  Take all your focus bonuses in crafting items, pop out 30 items with strength 8+ and with some thought put into it, you become a +8 Magic Item of "Do Whatever I Want as Much and as Often as I Want."  Especially if you spend a couple or three item slots for 4-6 potions (which you can leave undefined and during play declare the contents of them as you go with a Lore roll).

great! that helps SO much, and it took a bit of stress off my mind since this is the introduction to this game for most of the players in the group and i didn't want to make it too impossible on them.

There are two ways to find out how much oil is in your car, one is to drain it all out and measure it, the rest of us use the dip stick.

Test your players early on without trying to kill them, arrange for them to find/steal/inherit/be given the plot hook item and low to mid threat level bad guys (whatever you think is low to mid level) attack them to get it from them.  They aren't looking to kill anyone and it would be perfect acceptable for them to just knock half the party senseless, take the item and leave.  Just don't have it matter to the story, if they get the item, fine, the PCs are drawn into the story by wanting to get it back and hopefully getting some payback.  If they don't get the item, the PCs should be curious as to why it's wanted and the bad guys at this point know all about it and just wanted to get it from the PCs before they could study it or what have you.  Either way, you'll have a baseline for the PCs capabilities without needing to hurt them too much and your story stays on track.  Go up or down from there as needed to get the challenge you want.

No, that's how it works. Though he should be able to Tag his newly self-inflicted Moderate and Extreme Consequences as well, at least, IMO.

Don't short yourself either, you get one fate point per consequence you have when you're taken out of a fight, so toss in four fate points worth of invokes on appropriate aspects for another +8.  Death curses are serious business.

Nomad, this is a Role Playing game, nobody is going to not make a duel wielding pistol user just because it is impractical in real life because this isn't real life.

They would in my gaming group.  Between a reenactor who fights with live steel who was an army ranger, a medic who did a tour in Iraq, computer tech who is also a competition pistol shooter, a psychologist, a musician, a corrections officer who farms and hunts; we've got quite a few bases covered in my gaming group when it comes to what is or isn't impractical in real life and none of us are shy about calling "Bullsh*t" when something just wouldn't work.  We consider realism important in maintaining our suspension of disbelief.  We'd no more allow a mortal to duel wield pistols at separate targets than we'd allow a mortal to revive someone after an autopsy.