#obscuration

[ultra-phthalo]

Lasting Obscuration Doctor Nowhere

[noblecrumpet-dorkvision]

How to beat Darkvision

If you're upset about your players all having Darkvision when all you want is to make it hard for them to see, then you aren't alone. Now, I understand that it's a perfectly valid thing to have Darkvision in D&D. However, it's also perfectly valid for a DM to need to have things hidden or at least difficult to spot for narrative, puzzle, or combat reasons. So here are some simple tools that a DM can use to reclaim the night.

Understand the Rules

First of all, many people don't understand how Darkvision works in D&D 5e (myself included for a while). If everyone in the party has Darkvision and they opt not to use light while exploring a dark space, the creatures don't see things clear as day. "Dim light becomes bright light and darkness becomes dim light" is what the rules say about Darkvision. Darkness is technically still lightly obscured. Therefore, players will have disadvantage on Wisdom (Perception) checks. Their passive Perception gets -5. They are still sitting ducks for an ambush. It will likely take just one surprise attack to make players realize that while, yes, it's easier to sneak in the dark, it's also harder to see.

Not to mention Darkvision doesn't let creatures see in color. So if they choose to go this route, they may miss out on identifiers like the telling robes of a Red Wizard.

Change it Up

It's your campaign, so you can change Darkvision a bit to suit your needs.

In my campaigns, I operate under the assumption that players can't read text or see patterns on cloth if they don't have light. For instance, an elf in the dark could see a sheet of paper, but not the words written upon it. Sort of like a 3D model without textures. That may not be the way night vision goggles work, but this is a fantasy setting, so I can do what I want. It forces players to cast light or light a torch every once in a while.

Back in older editions of D&D, there was Infravision and Ultravision. Infravision could see into the infrared part of the electromagnetic spectrum, so they could detect heat. You could change Darkvision to this, meaning that they could only see heat sources in the dark. Walls would block this unique type of vision, and some creatures would be invisible (like reptiles, constructs, or undead). If players had a hot light source, it would blind the creature to other heat sources while it's lit.

Ultravision lets you see the other side of the spectrum, which doesn't help very much from a standpoint of detecting creatures. However, in AD&D it was understood that magic emits ultraviolet light. This essentially let such creatures see the influence of magic. I would stay away from this one as it nearly replaces detect magic. If you were wondering, players could have both types of vision and it was called Supravision (it also let creatures detect the school of magic when using Ultravision).

Use Obscuration

If you aren't comfortable with changing Darkvision and it's rules, you can still put creatures with Darkvision on equal footing with other species by using the rules for obscuration. 

If looking into an area that is lightly obscured, a creature gets disadvantage on Wisdom (Perception) checks and -5 on passive Perception. A creature can hide in a lightly obscured area. If looking into an area that is heavily obscured, a creature is effectively blinded. Therefore they automatically fail sight-related Perception checks, and also have disadvantage on attack rolls.

Here are some things those dark dwellers can see through just as poorly as everyone else:

Light Obscuration:

Mist

Webbing (such as the web spell)

Light Foliage

Light Precipitation

Swarms of Insects (such as the insect swarm spell)

Heavy Obscuration:

Fog (such as the fog cloud spell)

Magical Darkness

Heavy Foliage

Heavy Precipitation (such as the sleet storm spell)

Invisibility

[fieriframes]

[A man sitting at a table in a restaurant, caption: I shall overcome any obscuration.]

[alexanderrogge]

Bob King - Harvest Moon Takes a Quick Dip in Earth's Shadow:

Harvest Moon Takes a Quick Dip in Earth's Shadow

Partial lunar eclipse will be only time the Moon ducks into Earth's umbral shadow in 2024. The Moon occults Saturn and hides Pleiades stars.

HarvestMoon #Moon #PartialLunarEclipse #Eclipse #Obscuration #Astronomy

[ijtsrd]

Significance of Area of Obscuration and Derivation of General Expression by Method of Integration

by Gourav Vivek Kulkarni "Significance of Area of Obscuration and Derivation of General Expression by Method of Integration"

Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-1 , December 2020,

URL: https://www.ijtsrd.com/papers/ijtsrd35869.pdf

Paper URL : https://www.ijtsrd.com/mathemetics/calculus/35869/significance-of-area-of-obscuration-and-derivation-of-general-expression-by-method-of-integration/gourav-vivek-kulkarni

callforpaperarts, artsjournal, peerreviewedjournal

In a number of Engineering applications, there are certain governing variables that bear the potential to possess a major part of the control towards the success of the process. Some of these variables may be independent while others are dependent on each other is some or the other manner. In applications involving metered quantity of fluid flow, radiation heat transfer and so on, one of such governing variables is the flow rate. Flow rate may refer to that of any fluid or radiation or solids in certain cases. As flow rate depends on the area of opening that is available for flow, it is customary to either determine the area of opening or that of obscuration. In this paper, initially the physical significance of area of obscuration in applications related to fluid flow, radiation heat transfer, packaging applications and photo sensors shall be elaborated to establish a premise for the later derived general expression for determination of the area of obscuration for a combination of two circles with different radii, with one placed at any arbitrary point in space. This general expression shall be deemed to be applicable for provided certain necessary condition is met with respect the relation between the radii of the two circles and the distance between their centres. The derived general formula shall be verified towards the end to confirm the validity for any arbitrary case. 

[ijtsrd]

Determination of Area of Obscuration between Two Circles by Method of Integration

by Gourav Vivek Kulkarni "Determination of Area of Obscuration between Two Circles by Method of Integration"

Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-1 , December 2020,

URL: https://www.ijtsrd.com/papers/ijtsrd35863.pdf

Paper URL : https://www.ijtsrd.com/mathemetics/calculus/35863/determination-of-area-of-obscuration-between-two-circles-by-method-of-integration/gourav-vivek-kulkarni

ugcjournallist, listofugcapprovedjournals, researchpublication

Obscuration is the phenomenon of covering of a certain percentage of area of an object by another. It can be a governing variable in radiation heat transfer, fluid dynamics and so on. Although modern day analytical tools allow determination of area of obscuration, the non availability of handy formulae for theoretical calculations has lead to this study. In this study, the method of integration shall be used to determine the area of obscuration for various cases. Two circles of different radii shall be considered for this study. Various positions shall be considered and based on the combinations obtained, expressions for the area of obscuration shall be derived. This study aims at enumerating and exploring various cases so as to pave way towards a further study of general formulae to arrive at required expressions. Thus the theoretically obtained area can be used in various calculations as and when found of necessity. 

[fierifiction]

I shall overcome any obscuration. The one who has fallen asleep is dead. The one who is now alive now rests. All who are dead are saved from death by the light of the sun." (Judaism, The Sun-Goddess, 14th ed., pp. 29-40). I do not propose to be a religious fanatic, because it makes me as rational an atheist as many who are in agreement with the traditional religious system".