Awareness differences smoke and fog

[Aerotime]

What are the differences of “awareness“ between smoke and fog?

[Taja the Barbarian]

Aerotime wrote:

What are the differences of “awareness“ between smoke and fog?

By default, fog blocks all vision beyond 5 feet (basically providing Total Concealment), while Smoke merely provides concealment (note that specific 'smoke' or 'fog' effects might have different rules, but these are the general rules for these effects).

Chapter 11: Game Mastering / Environment / Environmental Rules / Smoke Effects wrote:

Source Starfinder Core Rulebook pg. 400

A character who inhales heavy smoke must attempt a Fortitude save each round she’s within the smoke (DC = 15 + 1 per previous check) or spend that round choking and coughing. A character who chokes for 2 consecutive rounds takes 1d6 nonlethal damage. Smoke obscures vision, providing concealment (20% miss chance).

Chapter 11: Game Mastering / Environment / Weather / Fog wrote:

Source Starfinder Core Rulebook pg. 398

Whether in the form of a low-lying cloud or a mist rising from the ground, fog obscures all sight beyond 5 feet, including darkvision. Creatures 5 feet away have concealment (20% miss chance).

Chapter 8: Tactical Rules / Combat Modifiers / Concealment wrote:

Source Starfinder Core Rulebook pg. 253

Originating from sources such as dense smoke and battlefield position, concealment obscures precise senses and imposes a miss chance on attacks. When you have concealment, it’s harder for enemies to see you clearly. This might be due to your position on the battlefield, or it might be due to another effect that makes it more difficult for enemies to perceive and hit you with an attack.

To determine whether you have concealment from a creature’s ranged attack, choose a corner of the enemy’s square. If any line from this corner to any corner of your square passes through a square that provides concealment or the border of such a square, you have concealment. Also use these rules when a creature makes a melee attack against a target that isn’t adjacent to it.

When a creature is making a melee attack against an adjacent target, the target has concealment if its space is entirely within an effect that grants concealment.

Additionally, some effects provide concealment against all attacks, regardless of whether any intervening concealment exists.
Concealment Miss Chance
Concealment gives the target of a successful attack a chance that the attacker actually missed. This is called a miss chance. Normally, the miss chance for concealment is 20%. Make the attack normally; if the attacking creature would hit, the target must roll a 20 or lower on a d% roll (see page 513) to avoid being struck. Multiple concealment conditions do not stack.
Varying Degrees Of Concealment
Certain situations can provide more or less of a miss chance than typical concealment. In this case, it is up to the GM to determine a character’s degree of concealment.
Total Concealment
If a creature has line of effect to you but not line of sight (see page 271), you have total concealment. An enemy can’t attack you when you have total concealment, though it can attack into a square it thinks you occupy. A successful attack into a square occupied by an enemy with total concealment has a 50% miss chance (instead of 20%).
Ignoring Concealment
Concealment might be ineffective. Dim light or darkness doesn’t provide concealment against creatures with darkvision. Creatures with low-light vision can see in dim light as if it were normal light.

Concealment (total or otherwise) does not guarantee a lack of awareness, but it does generally allow you to make a Stealth check to Hide (with a huge bonus from Total Concealment).

Skills / Stealth (Dex; Armor Check Penalty) / Hide wrote:

Source Starfinder Core Rulebook pg. 147

You can use Stealth to hide if you have either cover or concealment (or a special ability that allows you to hide in plain sight), or if you have successfully created a diversion with the Bluff skill. You can attempt a Stealth check to hide either as a move action (if you are planning to stay immobile) or as part of a move action. If you move at a rate of half your speed or less, you take no penalty to your Stealth check. If you attempt to hide while moving more than half your speed or after creating a diversion with Bluff, you take a –10 penalty to your Stealth check; these penalties are cumulative if you do both. The check is opposed by the Perception checks of creatures in the area that might detect you. A creature that fails the opposed skill check treats you as if you had total concealment as long as you continue to have actual cover or concealment. A creature that succeeds at the opposed skill check either sees you or pinpoints you (see page 260) in situations when you have total concealment. If you lose actual cover or concealment during your turn, you can attempt to stay hidden, but only if you end your turn within cover or concealment.
Invisibility and Hiding
Source Starfinder Core Rulebook pg. 148
If you are invisible or benefit from total concealment, you gain a +40 bonus to your Stealth check as long as you remain immobile. You are considered immobile if it is your turn and you have not yet moved or if you have not moved since the start of your last turn. If you are invisible but not immobile, you instead gain a +20 bonus to your Stealth check. Typically, a creature cannot attack you if you are invisible or have total concealment unless the creature pinpoints you with a successful Perception check. (Invisible creatures can still be heard, smelled, and felt, and might do something to make themselves known to those who succeed at Perception checks; see Invisible on page 264 in Chapter 8.) Even then, the attacking creature has a 50% miss chance against the pinpointed creature.
Attacking from Hiding
Source Starfinder Core Rulebook pg. 148
If you are successfully hiding from a creature, that creature is considered flat-footed for the purpose of your first attack from hiding. If you remain invisible after your first attack, that creature is considered flat-footed against your attacks until it succeeds at a Perception check to locate you or until you become visible.

It should be noted that there are a lot of creatures in Starfinder with non-visual senses that would not be hindered by either smoke or fog