Ok- first off, the game in question isn't DF, but I'm coming here because you guys are good, and because you have blocks in your version of fate (unlike FateCore, which took them out).
We have a problem. Our group is in a survive-the-night scenario. They need to hold out in a semi-secure area against a zombie horde until the cavalry arrives- at most a single night (it'll arrive when dramatically convenient, but the longer they hold out, the greater the benefit to the story, and the greater the game reward)...
My players are all human, but they all wanted to be a reasonable cross-section. We have one Boxer, but other than him, no one has a combat skill at peak (+4) [unless you count athletics, we also have a fitness nut who runs a lot].
The players have long enough before the horde to run a prep montage... in essence, they get two actions with lasting effect (the group had long ago ruled that two was a reasonable limit, to keep either them from using preparation time to get the run of the show. Actions-in-play are unlimited, but a montage gets 2-3 and we move on). Typically, the players have used this in the past for navel-gazing maneuvers (standard difficulty 3)- the boxer would practice his footwork to limber up, the runner would stretch, the carpenter who-knows-his-way-around-an-axe would sharpen his weapons, and so on... The aspects, as part of the montage rule, are automatically semi-sticky (last until used, but don't have to be used right away like typical fragile aspects- this is the reason why there's a limit- the perk that balances the trade-off).
We're happy with the rule, and it has served us quite well in the past, innumerable times. That is, surprisingly, not the issue. Blocks and how they work are:
Since the carpenter has Craft +4 (with a stunt bringing wood-work up to +5), and Melee at only +2... the navel-gazing self-buff on his weapons is a crapshoot. Honing them or practicing with them would require him to roll a +1 (+2 = 3) to bank a single-use +2 bonus (in the form of an aspect).
So, he got the bright idea to set up a block- one of their available last-stand grounds is a smallish room, concrete walls, with high small windows (2' by 6") too small to get through... and a door that's been unhinged (literally had them removed- it was a storehouse, and someone removed them to raid it- everything's still intact). He can easily put the door back on- I'm not even really charging them for that, so to speak... but he wants to reinforce it using his craft skill. More power to him- instead of gambling on a mid-grade skill, he can bring his peak skill to the table.
Problem is, he gets two actions. Can he use both on the block?
Even if he can't, can the others reinforce it, and by how much?
There's also an academic in the group- ok with a shotgun (skeet shooting in college), but a good engineer by chance (academics +4, stunt applicable with only a little debate)... he can help out there, in design if nothing else.
The boxer's plenty strong- he could use his boxing to navel-gaze and bank a +2 on a skill that's already strong... or his might to add +3 to the block on a 0-roll, piling up all manner of heavy into the barricade to make it that much more... more.
You get the gist. We had to break session before we really got into this, because of time constraints... thank God, since it gives me time to think about how to handle it...
By my best guess, if I let every player act twice on the block, and simply add all their rolls together for a single effective block, and they all roll 0's... it'll be around a block rating of 60. Sure, the zombie horde might EVENTUALLY push through that (if I similarly let each of their attacks on it deplete it), but it would still be enough to get them through a helluva lot more night than I was ready to expect... and sounds pretty close to unreasonable, even given that I want to reward their moment of brilliance.
Even if I only let them act on the block directly once, they're likely to still pile all their eggs in one basket, by using their first action (each) to place a maneuver (gathering materials, etc) that are then tagged on the 2nd action... and get a block rating around 50. Even if I force them to only work with a single action for a single block, they can still pile everything in on this by loading up that one action with aspects, and creating a block at least around 30.
I also thought about saying sure- but each action is a separate layered block... this would result in 12 blocks ranging in strength from ~2 to ~6 (even assuming 0-rolls and no FPs). This might be the best way to go, with blocks lasting as long as they normally would (until overcome)... when a zombie overcomes a block, it fails, but then must face the next one in the list (any extra shifts could immediately overflow to taking out that one, if they're enough). This would AT MINIMUM buy the team 12 attacks (given the tight confines, probably 6 rounds minimum)...
Which brings up another problem- while the horde is working on tearing it down, what (besides limited supplies) is to keep them from repairing it from inside, and how do I best handle THAT?
The best idea I've had as far as my gut instinct for fair play goes is that the initial roll sets the level of the block, and any additional rolls either replace it, or add +1 to it (whichever is better). This will produce a solid but not impossible block, and allow wiggle room for repair... but the players would get more bang for their buck setting up aspects on the primary actor than contributing to his roll after the fact.
In essence, I just need a think-tank to tell me how they handle blocks in this kind of scenario. Can you take an existing block (one that's still standing ONLY because it hasn't been breached, not because it's got a fixed duration), and enhance it? It seems intuitive that it should be possible, but then, how is that best handled systems-wise?
Thoughts, opinions, advice?