Fogs & 5 Foot Step

[Necrosnoop110]

Why do the fog spells generally include the clause "A creature can’t take a 5-foot step while in [fog x]." One example is Solid Fog.

Q1: What's the underlying reasoning behind this extra clause to restrict 5-foot steps? Especially since it already states that "any creature attempting to move through it progresses at a speed of 5 feet."

Q2: What happens when a creature is larger than the total volume of the cloud and only a portion of the creatures body moves through the cloud? Is that creature restricted in movement if only a portion of its body passes through the cloud? 

Peace,
Necro

[wotmaniac]

A1:
Here's my take -- I think that the intent is twofold: 1) keep people from abusing the movement/action economy (within the given context, that is); 2) a nod to verisimilitude.
1) Without the "no 5-ft step" restriction, you'd be able to take a full-round action and still move 5 feet -- that isn't really fair to the guy that is using his movement .... "hey, the guy who took his full-round action is still able to move half as far as the guy who dedicated his round to moving" or "WTF - using a free action to do the same thing that requires a move action"  Also, consider this from the SRD:

In some situations, your movement may be so hampered that you don’t have sufficient speed even to move 5 feet (1 square). In such a case, you may use a full-round action to move 5 feet (1 square) in any direction, even diagonally. Even though this looks like a 5-foot step, it’s not, and thus it provokes attacks of opportunity normally. (You can’t take advantage of this rule to move through impassable terrain or to move when all movement is prohibited to you.)

You can’t run or charge through any square that would hamper your movement.

2) typically, a 5-ft step is basically considered to be rather effortless and is simply done in the course of everything else you do in that round.  If the fog is so restrictive on your movement that it takes an entire move action to simply move 5 feet, then it doesn't really make since that you can move the same distance effortlessly.

A2:
Yes, you are still restricted:

If you occupy squares with different kinds of terrain, you can move only as fast as the most difficult terrain you occupy will allow.

I know that that particular sentence says "terrain", but I think that the overall intent is clear (i.e., when you take in the entirety of the movement rules)

[Garryl]

Why do the fog spells generally include the clause "A creature can’t take a 5-foot step while in [fog x]." One example is Solid Fog.

That's just the spells based on Solid Fog that reduce your movement speed to 5 feet. I don't see why you're saying "generally", since only Solid Fog says that (although Acid Fog inherits it). It's not just one example, it's the only example. The fog spells that don't affect movement speed (Fog Cloud and Obscuring Mist) have no such limitation.

Q1: What's the underlying reasoning behind this extra clause to restrict 5-foot steps? Especially since it already states that "any creature attempting to move through it progresses at a speed of 5 feet."

It's actually part of the normal 5-foot step rules that you can't take a 5-foot step when your movement is reduced to only 5 feet. Thus, the text in Solid Fog is as much a reminder of the normal rules as anything.

[NunoM]

A1.: You must spend a move action, to move 5ft.. Unless magically assisted, you'll never be able to perform, say, a full-attack action, in a round in which you moved 5ft. inside a "Solid Fog".

A2.: Already answered, and correctly IMHO, but i'll just add my 2 cents: i always considered "Solid Fog" as a sort of vertical sticky mud pool. Even if only your hand is caught in it, you can't move well enough, because it sticks like glue...

[Necrosnoop110]

Why do the fog spells generally include the clause "A creature can’t take a 5-foot step while in [fog x]." One example is Solid Fog.

That's just the spells based on Solid Fog that reduce your movement speed to 5 feet. I don't see why you're saying "generally", since only Solid Fog says that (although Acid Fog inherits it). It's not just one example, it's the only example. The fog spells that don't affect movement speed (Fog Cloud and Obscuring Mist) have no such limitation.

This really was just offhand language use to avoid some one saying "hey you know that not all fog spells do this." But instead I got someone pointing out the opposite. 

It is not true that Solid Fog is the only example of the 5-Foot step clause, if you really want to get technical. D&D has a bajillion fog and fog-like spells. Off the top of my head I can you tell you that Freezing Fog also includes the "can't take a 5-foot step" clause. If I searched I suspect I could find others. 

[Necrosnoop110]

A2.: Already answered, and correctly IMHO, but i'll just add my 2 cents: i always considered "Solid Fog" as a sort of vertical sticky mud pool. Even if only your hand is caught in it, you can't move well enough, because it sticks like glue...

Excellent way to look at it, thanks.

[linklord231]

This might be a little off topic, but how does Solid Fog interact with a flying creature that must maintain a minimum forward speed?
Say there's a big ol' dragon bearing down on the party.  The Wizard drops a Solid Fog on it in midair.  On his turn, the dragon flies into the fog, but can only advance 5' in.  Since he didn't move half his speed forward, does he stall and start falling?  Or does Solid Fog replace his normal speed with "5 feet", and since he moved that far, he can continue flying?  If he stalls and starts falling, does he fall at 5' per round until he exits the Fog, or do the falling rules trump and he falls 150' immediately?

[Jackinthegreen]

This might be a little off topic, but how does Solid Fog interact with a flying creature that must maintain a minimum forward speed?
Say there's a big ol' dragon bearing down on the party.  The Wizard drops a Solid Fog on it in midair.  On his turn, the dragon flies into the fog, but can only advance 5' in.  Since he didn't move half his speed forward, does he stall and start falling?  Or does Solid Fog replace his normal speed with "5 feet", and since he moved that far, he can continue flying?  If he stalls and starts falling, does he fall at 5' per round until he exits the Fog, or do the falling rules trump and he falls 150' immediately?

The wording of "progresses at a speed of 5 feet" is sadly too unclear to make a truly definitive ruling I think.  It'd probably be easiest to say that all its speeds become 5 feet, thus it can maintain its minimum forward movement.

[NunoM]

If the "Solid Fog" hits a dragon in midair it will certainly slow him down a lot.

Personally, unless the dragon has Good or Perfect maneuverability, i would consider it to be stuck at least 5ft deep in the fog. This is only to abide by the rule that: even if only 5ft of a creature gets stuck in the fog, the fog affects it completely. When this happens, the dragon would start falling (probably hanging by it's head and neck, which would be hilarious!), but at the rate the "Solid Fog" allows:

A creature or object that falls into solid fog is slowed, so that each 10 feet of vapor that it passes through reduces falling damage by 1d6.

However, "Solid Fog" has a height of 20ft. (inherited from Fog Cloud). After falling 20ft. the dragon would be able to flap his wings once and be on his merry way again.

[linklord231]

If the "Solid Fog" hits a dragon in midair it will certainly slow him down a lot.

Personally, unless the dragon has Good or Perfect maneuverability, i would consider it to be stuck at least 5ft deep in the fog. This is only to abide by the rule that: even if only 5ft of a creature gets stuck in the fog, the fog affects it completely. When this happens, the dragon would start falling (probably hanging by it's head and neck, which would be hilarious!), but at the rate the "Solid Fog" allows:

A creature or object that falls into solid fog is slowed, so that each 10 feet of vapor that it passes through reduces falling damage by 1d6.

However, "Solid Fog" has a height of 20ft. (inherited from Fog Cloud). After falling 20ft. the dragon would be able to flap his wings once and be on his merry way again.

That sounds reasonable, except for the last part.  A creature who stalled while flying needs to make a DC 20 reflex save in order to regain control of his fall, and only after it falls the first 150'.

[NunoM]

That sounds reasonable, except for the last part.  A creature who stalled while flying needs to make a DC 20 reflex save in order to regain control of his fall, and only after it falls the first 150'.

Ah, yes! Thanks for the reminder!
Did some google-fu to brush up on that. Here's the source: All About Movement (Part Four) and All About Movement (Part Five)