Having fun with game mechanics....

[Drul Morbok]

Hey everybody,
8 or 9 years ago, I had my first try on GMing, a single-player campaign with a friend of mine who had studied some years of chemistry. We quickly agreed that the game world did not have to be consistent with what he had learned at university, but that the rules for some in-game effects should be consistent enough to allow for their own scientific explanation.
Of course this would be too big a claim to discuss in all aspects, but we especially had two favourite topics: Invisibility and darkvision as seen in 3rd ed. D&D.

Invisibility, of course, has always been a popular topic at almost any time in almost any culture. So I already had read some SciFi literature containing some thoughts about it, the main one being that an invisible person should be effectively blind: If you become totally translucent, or find some way of bending or teleporting the light around you, there will by definition be no light reaching your retina. One might find a different explanation of how "seeing" actually works, but I think that would be overkill.
So either you should keep your visual organs visible for them to work (the retina alone would not be enough since it relies on the light being focused by a lens and dimmed by the pupil), suffer those consequences, or find an in-game way around it.
Another question that always intrigued me is the idea of invisibility as an illusion, either in the mind of the onlooker, or as a hologram-style "chameleon suit" portraying the background. In either case, people can not see you while you can still see them - but they also should not be able to see what's happening behind you. In a modern example, if such an insvisible person stepped in front of a running TV screen, would other people still actually see what's running on TV?


I should add that none of those are yes/no questions. I have not found any "best" solution so far, and I certainly don't want the topic to go the way of a general debate ;-)
I rather think that each consideration could make for some interesting roleplaying situation. Even if you don't care about the laws of optics, it might still be interesting to have players putting some ring of her finger becoming blind, while becoming invisible for the others. Than put on that smart-ass smile while they try to remove curses, or cure blindness 
I mean, still than, there could be several implementation of spells that all achieve some different kind of "invisibility", some of them even being outright fraud to the credulous buyer.


The question of Darkvision turned out to be a somehow sociological one 
First of all, we agreed that it was a kind of misnomer, since vision and seeing are so closely tied to light-based effects, that non-light based perception should not be called "vision" or "sight". For lack of other words, I'll use them anyway...
We agreed that when seen with darkvision, there are neither reflecting surfaces, nor translucent materials. A perfectly polished silver plate would look almost the same as a perfectly even and even-colored stone plate - or a glass plate. And if you're looking "in" a mirror, you see the same flat surface. So with darkvision only, it's pretty hard to know how you really "look like". I decided that this was going to have "some" impact on such races' self-perception as well as behavior in general...
To spice it up, I added the unexplained fact that gold is the only material that actually "reflects" darkvision. Most sentient being consider this a mystical or holy property of gold, and actually believe that they are being granted "visions" when looking at gold (and maybe they are even right, who knows  ). That's why some underground races downright crave for gold 

If even perfectly clear water is deeper than a few inches, so. using darkvision can't tell how deep it is, or what's in there, so most underground dwellers tend to be very cautious about any body of water deeper than a puddle....
To make such underground dwellers somehow surface-compatible, I decided that they additionally had conventional vision - but not necessarily the best of both combined 
Followind D&D terminology, if you have darkvision, it has some specified range, usually 90 feet i think - which also is the limit of depth perception! A D&D dwarf standing on an open field in broad daylight might feel like within a globe with a radius of 90ft, the walls displaying moving pictures. He would almost surely fail if he was trying to aim a ranged weapon, or estimating any distance, beyond that range.
Looking upwards to the sky for him would be some kind of equivalent of a human looking down into a seemingly bottomless hole.

This might be a rather bad basis for a long-term campaign including such races as PCs, but right now writing this, I'm having a creative flash 
In this year's after-X-mas session, I'll have all PCs be dwarves that have to leave or abandon some undergorund dwelling and travel the surface...suffering the aforementioned consequences for the duration of the session. They'll never know how far a Mountainis away, they can't navigate by the stars, and they most likely don't understand surface cartography, except for the "ranger" with an ancient map...


Maybe it's a personal trait, but I rather dislike this omniscient kind of magic that makes spell always work out the way the caster intends and need them to. Like "detect poison" - even in our modern world, there still often seems to be surprisingly little agreement on what qualifies as dangerous substance under which circumstances 
As above - no general "best" solution, but also the idea that it might be nice to have players find a ring of detect poison, to find out that it reacts to rather small concentrations of alcohol - by giving a rather annoying mental alert. Or make it a lout BEEP that can't be turned off. And since the ring requires one week of constant wearing to attune itself to the wearer's metabolism, the player can't take it off for an occasional sip of ale 

Maybe as another personal trait, I just like adding flaws to benefits, and benefits to flaws. I think David already posted something similar, so I'm not claiming to express a new idea...rather the other way round: I think this site kind of influenced my creative work in that direction, so I enjoy contributing to it and feeling like giving something back...
So I hope those that have read so far at least somehow enjoyed it...

Drul

[David Roomes]

I always enjoy thoughtful and well-reasoned contributions here on the forum.

So, I have a couple of responses. I'll go through the topics in roughly the same order that you brought them up. With regards to invisibility and darkvision... I and the players usually discuss and agree the mechanics of those two things early on. The specifics might vary depending on the specific game we're playing, the world we're using, the race that the player is playing, etc.

Invisibility

Bending light is the most common trick. Regarding the users ability to see, whether the light is being bent by magic or technology, I assume that the inventor of that invisibility would have taken sight into consideration. The invisible person NEEDS to see. So, if you have the ability to bend light, you probably have the ability to analyze and emit light. In other words, your spell (or tech) records and quantifies the light that would have reached the user's eyes. It then bends those light rays along with all the others, but duplicates those photons and sends them on their original path. So, the invisible person can still see but all the light rays are still being bent. This would require energy (because you are creating photons), but not much compared to the amount of energy required to bend light in the first place. The number of photons being duplicated (for the eyes) is a tiny fraction of the total number of photons that are being warped around the person. A good example of light bending would be the Predator's combat suit.

Invisibility by illusion is simply an illusion. That is, if you are simply affecting the mind of another person, then it's an illusion. It's all in the victim's head. Treat it like any other illusion.

Invisibility by a chameleon effect... well, this depends on how good the chameleon effect is. A poor example of the chameleon effect is the chameleon itself which is an opaque creature which can change colors to a limited degree. Better than the chameleon is the octopus and the cuttlefish. Those two are amazing. Both have some astonishing abilities to change skin color to match whatever is behind them. Check out videos online. I figure really advanced technology or fantastic magic would be able to do even better than the cuttlefish. So if someone with a really good chameleon suit (or spell) were to step in front of a running TV screen, you could still see the moving TV image... although depending on how good the effect was, it might be delayed or distorted. I think the exact limitations and results would be up to the game master. I figure magic, whether your replicating a background like a chameleon or bending light waves, would be pretty good. But perfect invisibility would be very hard to do. I think it's more fun to have some sort of a distortion effect or some other flaw. I think Tolkien had something like that. I think the Ring in the Hobbit wasn't perfect. Didn't Bilbo cast a shadow when he was invisible? I disagree with the physics of an invisible object casting a shadow, but I like the idea of a "flaw" in the effect. That makes for good storytelling. Plus, you don't want player characters to get too cocky with their invisibility. It's more fun if there's a tiny flaw (or distortion) and a sharp eyed sentinel might notice it.

Darkvision

I like to keep darkvision (and all other types - infravision, etc) simple. Either the character's vision magnifies light so that he/she can see in very low light conditions. Or the character is seeing in the infrared (heat). Low light vision would be effective, but you would be very vulnerable to sudden bursts of light. Infravision, also has limitiations, I think. If it's really sensitive, you could see temperature variations on surfaces. So, depending on the environment, you might be able to navigate and walk around without bumping into things, but you wouldn't be able to see fine details or color.

If you go way back to first edition D&D, there was also something called "ultravision", which allowed you to see perfectly well in absolute darkness. Ultravision was never really explained very well. I think it was the ability to see UV light. One odd thing about it was that any magic (such as a nearby magic item) would spoil ultravision. No idea what they were thinking when they wrote that down. That implies that magic items emit UV radiation. I never really bothered with it. In all my years of gaming, it never really came up. I don't think anyone ever had it or used it.

I don't put artificial range limits on magic vision. It's like normal vision. You're able to detect something (photons, heat, whatever). What matters is source and intensity. So, if a character had thermal vision, I would allow them to see a massive heat source from a very great range... just as a person using normal vision can see a very bright light from a great distance.

Omniscient Effects

Regarding detect poison, I agree. Those omniscient spells are ridiculous. The term "poison" is a good example of an ambiguous term. So, when I run a game, a detect poison spell would only work on specific types of poison. And more specifically, it would only work on the types of poisons that the creator of that particular spell knew about and could "program" into the spell. I would allow a broad range of poisons since it might be possible to scan for particular chemical patterns and similarities. But anything really unusual or obscure that the spell's creator would have no knowledge of would simply not get identified as a poison and the spell would miss it.

To expand on your point, I hate "detect evil" spells or "protection from evil" spells and things of that nature. How does one define evil or good? Isn't that completely arbitrary? Doesn't that depend on your point of view? So... my solution was to completely throw out the entire alignment system. When I run D&D there is no alignment. Player characters don't have to choose an alignment. Spells, items and effects can't discriminate based on alignment.

I even take it one step further. I think everyone knows that I don't like the concept of "classes". So, when I run a game, spells, items and effects can't discriminate based on class either. How does one define "fighter" or "thief" in the real world? Race you can determine based on DNA. But class? What makes one person a fighter and the next person a thief? Again... too ambiguous.

I'm getting a little long winded here (as usual) so I'm going to wrap it up.

By the way... good topic!