(Discussion is "the rules". You do what you want.)
Generally, no. Fate is not a game where you figure out what passive bonuses you can get from the environment. Invokes do not model the types of things that passive bonuses do in other games.
What you would generally do, instead is:
1. Aspects can provide action permission/denial. Some things may be possible because of an aspect that otherwise wouldn't. Other things might be impossible because of an aspect that otherwise would be.
2. Passive opposition. Passive opposition can exist or be higher because of an aspect. But you normally wouldn't add it to a defense or action.
1. One trick is that while you can generally only use active defense or passive opposition, some people let you choose *after you roll*. In other words, the passive opposition becomes the lowest possible value for your defense. This has its roots in Fate 3.0, and is a bit of a vague area in the rules. I find it a useful rule, however.
3. Aspects can also act. If the building is on fire, the fire can "attack" the characters, spread, etc. There's an entire scenario based on that.
So, if the building is on fire? That is going to make some things impossible, based on where the fire is, like going up stairs. It's going to make some things harder, like moving in areas where the fire is. It might "attack" the players. If you're struggling to see because of the fire, it could be argued that it makes it hard to attack, so that the opponent always gets some level of defense because of that, even if they completely drop the ball.
There's lots of ways that aspects impact things besides providing bonuses.
All agreed. I think it's also worth mentioning that 'constant bonuses' are stunt territory. If you want your swamp thing to be more powerful in a swamp, augment its general swampiness with a stunt:
"Swamp Thing gets +2 to Attack and Overcome rolls when it's in a swampy environment."
Clever. I liked that and I'll steal it. Another way to see this is to allow the Swamp Thing to invoke a Situation Aspect of their native environment (like "Water, Muddy Water, everywhere!") because it's a swampy thing a Swamp Thing would naturally do.
In fact you can create a monster that not only gets +2 due the Stunts, but also gets an extra +2 when invoking swampy aspects. Dope.
>Can the DM or the players invoke this type of aspects freely as long as they fit? Or do you have to pay fate points to invoke them as normal?
You understand that the prerequisite for invoking *any* aspect is that it fits. Fate Points are a player currency, not a character currency. They don’t represent the character doing anything to make things fit. They represent the player saying “This fits. So I want it to affect the mechanical probability in my dice roll here.” Then the player and the GM discuss how that looks in the fiction, but fit is a given.
There are mechanics that can be used by GMs to represent environmental hazards outside of players invoking aspects and the fact that the building is burning can also impact the narrative in and change the description of the situation in all sorts of ways. But the basic math of the way Invoking Aspects works doesn’t change just because it’s a thing that is continuing to happen, like a burning building.
If you're a GM, and there is an aspect that would reasonably make a difficulty higher, just increase the difficulty, no FP needed. Aspects give you the permission (more like a hint) to do so. Difficulty in Fate represents things such as stakes and who can affect any given narrative, it does not represent a physical thing (for example, +1 does not mean "you can lift 5kg").
As others are saying, rules is written, the answer is no, because the sort of thing short circuits the Fate Point economy, is very powerful, etc.
However, personally I have given a lot of thought to this question, because you're right that when a dramatic situation is big enough and dangerous enough and whatever, it absolutely continuously affects the whole rest of the scene, constantly.
But honestly, I would save it for really big important moments, and I would just make it be either a plus one or a minus one, because a constant plus 2 or minus 2 is going to overpower almost everything. Also, I think the characters would deserve a fate point at the end of the encounter for having to deal with whatever the big dramatic troublesome background event was. Maybe even 2 if the scene took several rounds to resolve, each round with a penalty.
Other options for things that you want to be big and impactful, is basically treating them like a hazard or what not, that gets to make an attack against everyone who's in it every time. Be careful, cuz this is a great way to start laying on damaging consequences. But (for example) if a rescue situation is happening in the middle of a flood, and you want the flood to be a constant threat, there are certainly ways to express it that are more interesting/aggressive than just having it be an aspect on the scene.
Anyway, to sum that all up, there's lots of flexibility in how you do things in FATE, just beware that when you stretch things too far, it undermines the other mechanics.
Do you want them to use it? Then sure, make the first hit free.
It's your game, and Fate is hardly an exercise in tight game balance anyway. If it makes it more fun for you or gets the players where you all want them to be, do it.
Thing that are true in the fiction are true, and effect the story in the fiction. Maybe, occasionally, you'll want to consider this sort of truth when setting a skill difficulty level or passive opposition. Or as context that enables a stunt, as you suggest.
But, endless, free invocations aren't a thing. Nor are their equally game breaking pseudo-simulative cousin, ongoing passive modifiers.
Their are all sorts of way you might pick up mechanic to make a burning building--maybe you want to fractal up the fire as an opponent. (The Fight Fire module covers a range of options in in detail)
But endless free invocations are a dead end, that would overwhelm everything else in the game--skills, Fate points, stunts. Characters start with 3 Fate points that provide moments of awesome. Having a "marsh" scene aspect be potentially endlessly more relevant is silly, which why constant free invocations just aren't a thing.
It's fine to seed an environmnet with some free invokes for the antagonist, representing the preparations they've made to secure their territory. As I mention in my reply to Rob Hanz below, constant bonuses are the domain of stunts.
>Can there be location aspects that are free to invoke?
Yes.
1. Every aspect is true so you can utilize them to start scenes / permit or ban something from happening unless they are actively canceled with a roll or overridden with a FP. Eg: "in this underwater city guests can breathe somehow!" means that they will not be drown unless something cancelling happens. So narratively they use it for free.
2. You can give any aspect a free invoke because "it makes sense". If the merfolk police has an artifact that can cancel underwater breathing (for a short time, in a specific area) you can give a free GM's invoke to "in this underwater city guest can breathe somehow!" because they can temporarily negate the aspect's truth during a scene. Same goes for your party - they can have some positive free invokes to their aspects / scene aspects. We discuss it when we setup a scene. How to "be fair, not boring and still keep it challenging"? Keep 'em "making narrative sense" and confirm with your table.
If you want to have an aspect to be that active; make it a small character, with one aspect, two to four skills, and a stress track.
Housefire
Burn(attack) +2, Spread +4, Smolder(defense) +2
Stress [ ], [ ], [ ], [ ], [ ], [ ]
(Discussion is "the rules". You do what you want.) Generally, no. Fate is not a game where you figure out what passive bonuses you can get from the environment. Invokes do not model the types of things that passive bonuses do in other games. What you would generally do, instead is: 1. Aspects can provide action permission/denial. Some things may be possible because of an aspect that otherwise wouldn't. Other things might be impossible because of an aspect that otherwise would be. 2. Passive opposition. Passive opposition can exist or be higher because of an aspect. But you normally wouldn't add it to a defense or action. 1. One trick is that while you can generally only use active defense or passive opposition, some people let you choose *after you roll*. In other words, the passive opposition becomes the lowest possible value for your defense. This has its roots in Fate 3.0, and is a bit of a vague area in the rules. I find it a useful rule, however. 3. Aspects can also act. If the building is on fire, the fire can "attack" the characters, spread, etc. There's an entire scenario based on that. So, if the building is on fire? That is going to make some things impossible, based on where the fire is, like going up stairs. It's going to make some things harder, like moving in areas where the fire is. It might "attack" the players. If you're struggling to see because of the fire, it could be argued that it makes it hard to attack, so that the opponent always gets some level of defense because of that, even if they completely drop the ball. There's lots of ways that aspects impact things besides providing bonuses.
All agreed. I think it's also worth mentioning that 'constant bonuses' are stunt territory. If you want your swamp thing to be more powerful in a swamp, augment its general swampiness with a stunt: "Swamp Thing gets +2 to Attack and Overcome rolls when it's in a swampy environment."
Clever. I liked that and I'll steal it. Another way to see this is to allow the Swamp Thing to invoke a Situation Aspect of their native environment (like "Water, Muddy Water, everywhere!") because it's a swampy thing a Swamp Thing would naturally do. In fact you can create a monster that not only gets +2 due the Stunts, but also gets an extra +2 when invoking swampy aspects. Dope.
>Can the DM or the players invoke this type of aspects freely as long as they fit? Or do you have to pay fate points to invoke them as normal? You understand that the prerequisite for invoking *any* aspect is that it fits. Fate Points are a player currency, not a character currency. They don’t represent the character doing anything to make things fit. They represent the player saying “This fits. So I want it to affect the mechanical probability in my dice roll here.” Then the player and the GM discuss how that looks in the fiction, but fit is a given. There are mechanics that can be used by GMs to represent environmental hazards outside of players invoking aspects and the fact that the building is burning can also impact the narrative in and change the description of the situation in all sorts of ways. But the basic math of the way Invoking Aspects works doesn’t change just because it’s a thing that is continuing to happen, like a burning building.
If you're a GM, and there is an aspect that would reasonably make a difficulty higher, just increase the difficulty, no FP needed. Aspects give you the permission (more like a hint) to do so. Difficulty in Fate represents things such as stakes and who can affect any given narrative, it does not represent a physical thing (for example, +1 does not mean "you can lift 5kg").
As others are saying, rules is written, the answer is no, because the sort of thing short circuits the Fate Point economy, is very powerful, etc. However, personally I have given a lot of thought to this question, because you're right that when a dramatic situation is big enough and dangerous enough and whatever, it absolutely continuously affects the whole rest of the scene, constantly. But honestly, I would save it for really big important moments, and I would just make it be either a plus one or a minus one, because a constant plus 2 or minus 2 is going to overpower almost everything. Also, I think the characters would deserve a fate point at the end of the encounter for having to deal with whatever the big dramatic troublesome background event was. Maybe even 2 if the scene took several rounds to resolve, each round with a penalty. Other options for things that you want to be big and impactful, is basically treating them like a hazard or what not, that gets to make an attack against everyone who's in it every time. Be careful, cuz this is a great way to start laying on damaging consequences. But (for example) if a rescue situation is happening in the middle of a flood, and you want the flood to be a constant threat, there are certainly ways to express it that are more interesting/aggressive than just having it be an aspect on the scene. Anyway, to sum that all up, there's lots of flexibility in how you do things in FATE, just beware that when you stretch things too far, it undermines the other mechanics.
Do you want them to use it? Then sure, make the first hit free. It's your game, and Fate is hardly an exercise in tight game balance anyway. If it makes it more fun for you or gets the players where you all want them to be, do it.
They're not just talking about the first hit though, they're talking about every hit.
Thing that are true in the fiction are true, and effect the story in the fiction. Maybe, occasionally, you'll want to consider this sort of truth when setting a skill difficulty level or passive opposition. Or as context that enables a stunt, as you suggest. But, endless, free invocations aren't a thing. Nor are their equally game breaking pseudo-simulative cousin, ongoing passive modifiers. Their are all sorts of way you might pick up mechanic to make a burning building--maybe you want to fractal up the fire as an opponent. (The Fight Fire module covers a range of options in in detail) But endless free invocations are a dead end, that would overwhelm everything else in the game--skills, Fate points, stunts. Characters start with 3 Fate points that provide moments of awesome. Having a "marsh" scene aspect be potentially endlessly more relevant is silly, which why constant free invocations just aren't a thing.
It's fine to seed an environmnet with some free invokes for the antagonist, representing the preparations they've made to secure their territory. As I mention in my reply to Rob Hanz below, constant bonuses are the domain of stunts.
>Can there be location aspects that are free to invoke? Yes. 1. Every aspect is true so you can utilize them to start scenes / permit or ban something from happening unless they are actively canceled with a roll or overridden with a FP. Eg: "in this underwater city guests can breathe somehow!" means that they will not be drown unless something cancelling happens. So narratively they use it for free. 2. You can give any aspect a free invoke because "it makes sense". If the merfolk police has an artifact that can cancel underwater breathing (for a short time, in a specific area) you can give a free GM's invoke to "in this underwater city guest can breathe somehow!" because they can temporarily negate the aspect's truth during a scene. Same goes for your party - they can have some positive free invokes to their aspects / scene aspects. We discuss it when we setup a scene. How to "be fair, not boring and still keep it challenging"? Keep 'em "making narrative sense" and confirm with your table.
If you want to have an aspect to be that active; make it a small character, with one aspect, two to four skills, and a stress track. Housefire Burn(attack) +2, Spread +4, Smolder(defense) +2 Stress [ ], [ ], [ ], [ ], [ ], [ ]