by Rob Donoghue (excerpted from this RPG.net thread)
"[T]the impact of maneuvers cannot be overstated, especially for purposes of teamwork, where the first PC sets up the maneuver and the second one takes the free tag to land a more palpable hit. Without that, fights can quickly be dull slugfests."
Take the following example:
A cavern, half-filled with water, deep beneath the foothills of New Zealand's Southern Alps. There were several statues of the Maori leviathan ( taniwha ) , big carved muvvas. Stalactites. And a big body of inky black water, from which, the heroes fear, some nameless fearful monster might emerge at any moment.
1. Using the scene
Breaking down the scene, I'd say the likely aspects I'd start with on the scene are:
* Murky Depths
* Giant Statues
Now, those are all pretty usable, and some possible tags include:
* Shooting a stalactite so it falls to pin something, granting a bonus to using guns for a maneuver
* An Acrobatic character swinging from the stalactites on an attack
* A character in the water misjudges their footing and slips in the murky depths
* A knockback or throw pushes a target towards the murky depths.
* The villains mooks make a surprise attack from the water, using the Murky Depths aspect on the surprise attempt.
* A strong character pushes down a statue, using might to make an attack or maneuver
* Our swinging character swings from a statue
2. Adding to the scene
Now, let's say our brilliant scientist decides to assert that this is the lair of the Hunga Munga worm, which comes out only to feed once every fifty years and it's next emergence is…RIGHT NOW! That's a little rough to do, mechanically, because there's no _action_ that comes from that. However, it's also pretty awesome, so if the GM is cool with it, absolutely roll with it.
So, instead, let's say that our brilliant occultist wants to make a declaration that this is the lair of the Hunga Munga Worm and that the words of summoning it are on one of the statues (which he tags for a bonus on the roll). That's a little more actionable because the character needs to take actions, specifically to get over to the statue and spend some time reading the chant, so it's actually well within the bounds of a declare, with the important qualifier that it says nothing about whether waking the Hunga Munga Worm is a good idea. It probably isn't.
Now, as an aside, as the GM, you control the valve on these sorts of things through your ability to control difficulties, so if these seem too silly or over the top, crank up the difficulty and call it a day.
3. Teaming up vs. Pounding
Assume three heroes and one villain, all with equal combat skills.
All three heroes attack the villain. They get lucky and 2 of them hit for small amounts of damage, say, MoS 2 each. The Villain has a decent stress track (Say, 8 boxes), so he can just take the hits, and his track now looks like 0XX00000. It's pretty clear that at this rate, it's going to be a while before anything interesting happens.
In contrast, let's say that heroes 1 and 2 perform maneuvers, putting "off balance" and "distracted" on the villain and #3 makes an attack, taking both of those free tags. His 2 MoS hit becomes a 6 MoS hit. It does not take many rounds like that (or better yet, taking one round of _all_ maneuvers, followed by a whammy of an attack next round) before the bad guy starts taking consequences. And if you've got 4 or more characters, the effect is even more pronounced.
Now, this demonstrates that maneuvers + attacks have _some_ mechanical advantages over just attacks, but there's one other factor which tips the scale - maneuvers are the best way to mechanically use your best skill against an opponents weakness. Since almost any skill can be used to perform a maneuver (if you can think of a clever enough way to use it), a clever maneuver can allow your social character to verbally berate his ninja opponent who he could _never_ hit with his fists. This application of strong against weak means every character can make a difference, and that goes a long way towards keeping everyone engaged.
Pull in Likely Aspects
Let's break these down into likely, unlikely and extreme. Hunga-Munga is pretty extreme, so I think we're covered on that, but let's look at some less crazy possibilities.
Likely aspects would be things which make sense in the context of the description, but they're just not something you thought of. Ideally, when a player suggests tagging such an aspect, your response is "Oh, right, that totally makes sense, and I would have put that in there if I'd thought of it myself."
For example, if someone in the scenario above interpreted the situation as "Slippery" then, yes, absolutely, give them the free tag.
Unlikely aspects will be the results of declares, albeit ones less extreme than Hunga Munga. A more restrained declare might be "Those mushrooms in the corner are rare Atlantean Fire Mushrooms! If you throw your torch on them, they'll explode!" (Amazing what passes for 'restrained' these days.)
Now, if a player does this, they're doing two things: Saying there are Mushrooms in the corner, and saying what they are. If you allow them to try to make the declare, you are implicitly accepting that the mushrooms exist (which does not seem like too much of a stretch in an underground cave) and you're rolling to determine if they're right about what throwing fire on them does.
If they fail the declare, you have two options. The first is boring - the mushrooms are perfectly normal and nothing happens. The second is that the mushrooms do something, but something _else_. The second is cooler because it lets the player say "This is important" but it lets you say (based on their roll) "yes it is, but not in the way you expected." In short, in these situations, you can always allow the declare attempt to add an aspect to the scene, but let the success or failure determine what it means.
(This is, by the way, why "Architecture" is a fantastic field of Art and Engineering is a fantastic field of science. These are the people who can reasonably declare "The whole building's about to collapse!")
In all of these cases, my rule of thumb is to err on the side of generous. They have just handed you the way to complicate their life on a silver platter. As much as we might talk about balance, free tags are a big deal for the players because they might run out of FP. As the GM, you have a bit less of a concern in that regard, so every aspect that a player adds to a scene is a way _you_ can make it cooler _and_ get your players more FP.
Thus, if a player suggests "Slippery" as an aspect for the scene, give them the free tag! It's an advance payment on the look on their face when, a little bit later, they dive for the idol and you hold up a fate point and say "It's pretty slippery".
PS - Oh! I completely forgot the middle ground, and this is well suited to tactical aspects. If an aspect might be on a scene, or it might be situational (such as if the fight is indoors, but may not really be a confined space) then remember that players may put aspects on the scene with their own actions. If the character starts pulling down bookshelves and making a mess, there might abruptly be less room to maneuver, so they may add the 'confined space' aspect to the scene themself.
PPS - And just to reiterate, there is no better yardstick than "Oh, right, that totally makes sense, and I would have put that in there if I'd thought of it myself."