Sil-like lighting in Angband?

[Nick]

I am considering introducing a cut-down version of Sil's lighting effects into Angband.

Specifically, I'm considering the possibility of some monsters having negative light radius - so they would be in darkness, and at higher levels surround themselves with darkness.

I see this working approximately as follows:

• Every monster (also the player) has a light intensity, which results in a light radius of that amount
• The default light intensity is 0, but both positive and negative intensities are possible
• Light intensity drops off by 1 (or increases by 1 for negative intensities) with every grid distant from the monster
• The light intensity on a given grid is the sum of all the intensities cast on it by nearby monsters
• A monster on a grid of negative intensity is not visible by ordinary vision (ignoring ESP and infravision)
• A monster on a grid of positive intensity is visible by ordinary vision
• On grids of zero intensity, the monster is visible or not as currently - so light intensity operates independently of whether a grid is lit or not

We could regard the current situation as torches and monster lights give light intensity 2, lanterns give intensity 3, and artifact lights (and lanterns of brightness) give intensity 4.

Introducing monsters with negative light intensity would mean that they move around in a patch of shadow, which would be cancelled out as the player's light source cast light on them.

I'm interested in opinions, especially from people with experience of Sil.

[wobbly]

I like Sil's lighting & think darkness monsters translated reasonably well in PCB-likes. I think the biggest thing to watch for in putting it in V is how it interacts with 'r'ead & 'm'agic. Is there going to be enough of it to overload a player's light & take away their escapes.

[Quirk]

So in general Sil's lighting works well, but clusters of enemies with their own darkness can as wobbly says overload the player's light level in ways that even within Sil can be quite fatal, and one of the remedies currently adopted is one I don't like very much: carrying extra light sources to drop on the floor to reinforce your own light. This is not particularly intuitive to new players and it's something I have vaguely noted as worth overhauling at some point - probably by boosting existing light sources a little and disabling items from glowing while not being worn.

If these monsters are reasonably uncommon and unlikely to be found together, having them be harder to detect by light alone until they are quite close is I think not necessarily problematic. Cancelling out player light may even be acceptable if they are both rare and slow moving. However, given that enemies will be harder to recognise until they're adjacent, I'd be cautious of this further increasing the necessity of ESP and Teleport Other. In Sil the remedies are carrying more +Light items and investing in skills such as Inner Light and Song of the Trees, which means the player has to diversify their approach to handle the problem; in Angband the optimal approach may be to continue doing what you would want to do anyway.

[Nick]

Thanks, that feedback is very helpful. I'm inclined to think that the combination of the rarity of darkness monsters and the range of options most Angband characters have should mean that the darkness effect won't be too overpowered. At least, there is plenty of scope for adjusting the parameters to achieve a good balance.

[Philip]

Having certain monsters have a dark aura would be an interesting way to make some of them more thematic (Ungoliant springs to mind). I think it would be great if V had it.

While lighting is being discussed, I would like to note that I feel like light radius ranging from 1 to 4 is a bit underwhelming really. One of the most consistently magical effects in the Tolkien universe is amazing light sources (Silmarils, the Trees, the Arkenstone, and Earendil turning into a star are all quite central to the stories they appear in, and even the Phial is one of the most important objects in LotR). Some of these light sources are in the game, and having them be "slightly better than a lamp" is a bit unimpressive. Given how powerful detection and ESP both are, I don't see too much of a problem with buffing (magical) light sources a bit.

[Wiwaxia]

Shadow hounds? No?

I love light effects in Sil, both gameplay-wise and thematically, and I'd be curious to see how it plays in V. I agree with Philip that you probably want more than 4 max light. Sil is understated enough that a light radius of three feels impressive (and you can stack light sources to get more) but V is... not understated, so piling on the glow is probably thematically appropriate.

[fph]

Sounds fun, but dropping lights on the floor to raise the light level feels gimmicky also in my view. I suggest that you drop that part, and use some formula like light_on_a_square = max(positive light level from sources & luminous monsters) - max(|negative light level from dark monsters|).

[Derakon]

Sounds like it's worth experimenting with. As a "safety" you might consider declaring the player's tile to always be lit if they have a light source, regardless of its strength level. You can gloss it as the player holding their light a few inches from the scroll/book they're trying to read.

[bio_hazard]

I like the idea, since it will make +light from equipment more useful and maybe make infravision useful past the first few levels too. But I can't help feeling this will only affect the early game since it will put even more premium on getting telepathy (or at least detect).

[Grotug]

tl;dr: what if artifact lights provided 'immunity' to -1 light?

~~~~~~~~~~~~~~~~~~~~~

I don't know that I followed all the particulars of Nick's post, but let me offer a simplified example using hypotheticals to present what I think would be a balanced form of implementation (light source radii in my example are the same as they are currently in the game).

I might just say that +4 light is quite a huge improvement over +2 light. Most rooms you enter when you have +4 light negate the need of illumination as a step of @ in any direction pretty much reaches the wall of most rooms. My point is +4 light is actually quite powerful and so I think a better solution is to leave the lights as they are but make artifact lights have a certain amount of immunity to negative light.

So in my example most monsters of unlight would have -1 to their radius. Very few monsters would have -2 (Shelob being the chief among them) and Ungoliant alone would have -3.

Artifact lights would be the same as they are now but would offer immunity to -1 light. That is, the Phial's illumination will not be affected by monsters with -1 light. For -2 light monsters the Phial loses 1 light. Against Ungoliant, artifact lights' illumination is reduced by 2, to that of a torch.

Therefore...

When facing Shelob with a torch, you will be in darkness as though you had no light (you would in fact be in -1 light). When facing Shelob with a lantern, you would still be in darkness at 0 light. When facing Shelob with a lantern of brightness, you will have the illumination of a torch, and with the Phial, it will lose -1 (instead of -2) light and you will thus have the brightness of a lantern.

When facing Ungoliant with a torch, you will have no light (technically -2 light). With a lantern -1 light. With a lantern of brightness you will still be in darkness (with 0 light) and with the Phial, you will have the light of a torch) (you will suffer -2 light instead of -3 light and go from +3 light to +1 light).

This would solve the problem of being in a position where you are blinded deep in the dungeon by the darkest of foes so long as you find a Phial or other artifact light (and it would thus make the Phial less trivial than it is now, and the dilemma of using a lantern of True Sight vs Phial more meaningful). If you don't find an artifact light by the time you're deep in the dungeon, well, hey, more thematic excitement to your spelunking! We are trying to make the deeper dungeon more dangerous after all. And of course you can stack light with various other ego weapons and artifacts (Cammithrim, I believe, has +1 light).

Yes, I like the idea of monsters so fel that they swallow the light. I think this is a great way to make the deeper dungeon more deadly!

[Nick]

OK, this is good - I have liked the idea more the more I've thought about it, and it seems like others feel the same. In particular, I've been doing almost exactly the same analysis as Grotug

A few minor points:

• Initially I'll have darkness from multiple monsters reinforcing, but if that's too dangerous fall back to the darkness being the largest shadow cast by an individual monster (like fph said)
• No light from light sources on the ground - easy to implement, because it's the current situation
• Ungoliant could even be -4 - so with the Phial you could see where she was, but not actually see her
• There's also the thought of spells/devices/the Phial giving brief more powerful illumination
• Priests perhaps should get some sort of light advantage; necromancers will already have the advantage that they can see in the dark

All in all I don't want it to be a major new killer of players, but I think it should present the player with new issues to deal with.

[Derakon]

A few minor points:

• Priests perhaps should get some sort of light advantage; necromancers will already have the advantage that they can see in the dark

Someone should be able to do Gandalf's shtick of making his staff shine really brightly.

[Philip]

I don't think there's any particular harm in going ham on Ungoliant's ability to cast dark - IIRC canonically she was able to maintain darkness even against the light of the two trees, a light source of which the Silmarils were a pale imitation. Also she's really really boring as it stands, with her only real ability being having high hp, which only really means she stays at max breath damage for longer than most monsters, and she takes up more resources than her stats would imply (however, she's unimpressive enough that usually the resources you expend are renewable). She could really use a gimmick. I think perhaps she should only really be beatable in a light contest by artifact light source using priests/paladins? Everyone else would just have to deal somehow.

I think a simple way of giving Priests a light advantage would be to make some of their spells create temporary zones of light light intensity as a side effect (some kind of Sunburst type spell), and give them spells that allow them to create glyphs of light, which would be permanent zones of light intensity.

I still think +4 light radius is a low maximum. It might work out ok in rooms (still seems kinda low though) but in corridors it's not great (congrats you have vision of 9 tiles), and it's quite useless for ranged attacks.

Basically I think if light is going to be overhauled it would be nice to stop having rods of light be such an integral pack component of every non-melee pack.

[luneya]

OK, this is good - I have liked the idea more the more I've thought about it, and it seems like others feel the same. In particular, I've been doing almost exactly the same analysis as Grotug

A few minor points:

• Initially I'll have darkness from multiple monsters reinforcing, but if that's too dangerous fall back to the darkness being the largest shadow cast by an individual monster (like fph said)
• No light from light sources on the ground - easy to implement, because it's the current situation
• Ungoliant could even be -4 - so with the Phial you could see where she was, but not actually see her
• There's also the thought of spells/devices/the Phial giving brief more powerful illumination
• Priests perhaps should get some sort of light advantage; necromancers will already have the advantage that they can see in the dark

All in all I don't want it to be a major new killer of players, but I think it should present the player with new issues to deal with.

I like this, with the proviso that it should only affect the player's ability to see things like terrain and monsters--books and scrolls should remain readable even if the player is carrying nothing but a basic torch and standing right next to Ungoliant.

[fph]

books and scrolls should remain readable even if the player is carrying nothing but a basic torch and standing right next to Ungoliant.

Actually, it could be interesting to experiment with the opposite change. Currently all 1-turn guaranteed escapes are based on reading (if I am not mistaken), so taking away the possibility to read in some very isolated contexts would be a new challenge.