Saturday, 6 April 2013

Monitors: cornerstones 1

So I mentioned previously that Monitors ought to include, at a minimum, the following elements:

  • Space travel
  • Cybernetics and general tech augmentation
  • Sneaking, observing, breaking in, tracking, decoding, arresting and other secret agent stuff
  • Armour
  • Spellcasting
  • Being a lizard

On reflection, I'd also add:

  • Fighting stuff
  • Being part of an intergalactic organisation

Okay, that's actually a pretty hefty set of objectives, but let's take a look at broadly how I might model the biggest one: being a lizard.

It ain't easy, being green. And scaly. And poikilothermic.

Playable reptilianity is going to be one of the major planks of Monitors, so I'm keen to make sure that it actually feels special. Things need to happen, mechanically, that make people feel like they're playing a reptile. Because not everything in the game is a reptile, this also means some clear distinctions should appear between the PC reptiles and any mammalian or avian NPCs they encounter.

Now, part of my background is in biology, so I'm always inclined to think about the actual science behind things, but I need to remember that scientific accuracy should play second fiddle to dramatic license. It doesn't matter exactly how it should feel to be a reptile; it matters how people think it should feel. This is a game. A system that perfectly reproduces the biological facts is going to miss the more important target.

Skin deep

Everyone knows that reptiles are well'ard. They have tough, scaly skins that protect them, which in the case of larger reptiles will turn aside claws and teeth, impede spears and swords, and maybe even deflect a bullet.


This is a lie.

It's been tricky tracking down any specifics - I'd have loved a scientific comparison of the skins of various critters, but alas, I didn't find one, only scattered bits of information. Mostly, it turns out, reptile skin is often less tough than leathery mammal skin; the individual scales are tough, but lie over a thinner membrane that's more vulnerable to splitting. Reptile skin takes longer to heal, too. The scales are not just physical protection; they reduce evaporation and help grip. Reptiles, on average, are no tougher than mammals of the same size, with thick fur to protect them. Chelonians are the main exception, with serious armour. Crocodilians have tough hide, though mammals of similar size are nearly as resilient.

However, that's not the point. Everyone knows that reptile skin is tough, and so reptilian PCs need to have tough scaly skin for them to feel like a "narrative reptile", regardless of what actual reptiles are like. Moreover, since the idea is for PCs to be reptiles by default, then there's less need to worry whether it's balanced with non-reptiles.

I'm probably going to use a damage-reduction scheme for armour, so the simplest thing is if Monitors have a point or two of armour to begin with, with exact values varying by lineage.

Right, that's the easy one over with...

In the blood

Reptiles are ectothermic poikilotherms with bradymetabolism. For those of you not obsessed with zoology, that means:

  • Ectothermy: they rely on external sources of heat, either air temperature or light
  • Poikilothermy: their body temperate can (and does) vary considerably (without killing them - not the case for mammals)
  • Bradymetabolism: their metabolic speed varies according to food availability and temperature, so they can be very active, very sluggish or completely torpid.

This means I really need a mechanism that will:

  • Take account of environmental temperature and light availability
  • Have poikilotherms taking on the environmental temperature
  • Have poikilotherms' activity vary according to their body temperature

I think this is really one of the things that could add something to this game. I'm not aware of a single game featuring body-temperature management as a common mechanic. More importantly, I think it can add to the narrative strength of the game in helping people feel reptilian. The traits I just listed mean that the relationship reptiles have to temperature sources and sinks is substantially different to that of mammals.

Walk in winter


You step out of the cave, into the chill February wind. Shuddering, you wrap your scarf tighter and stride out. It's a long walk back to the campsite, and the evening sun's weak. Several times you hunker down in the lee of bushes or rocks, letting yourself warm up again before you venture back outside. The thick clothes make you feel awkward and clumsy, but they keep the heat in.

The fastest route's over the fell, but it's windy out there and there's no point rushing when you can stay warmer (and sweat-free) on the long path through the woods. At least once you get back to the tent you'll soon warm up.


You step out of the cave, into the chill February wind. Shuddering, you wrap your scarf tighter and stride out. It's a long walk back to the campsite, and the sun's weak. You hurry out onto the fell, the shortest route; you can't waste a second. Every moment, the cold is leaching away precious heat, and with the setting sun this weak you've no way of regaining it. The thick clothes make you feel awkward and clumsy, but they keep the heat in.

Are you getting slower? You're sure you're getting slower already. It's windier this way, so you'll cool down faster, but the woodland path will take twice as long, and that might be time you don't have. You feel vulnerable, nervous; if anything jumps you in this temperature, your reflexes might not be good enough to save you. Occasional bushes shelter you for a moment, but there's no point stopping, you'll just keep getting colder. Let's just hope the tent will protect you until morning comes and you can soak up some rays. Let's hope it's a clear day.

Are you getting slower?

Busy train in winter


You squeeze your way into the train, and wait. It was cold outside, but within a couple of minutes you're wishing you'd stopped to take off the coat before you got on. And maybe the jumper. It's too crowded to think of it now.

You're getting hotter. You don't feel too well, actually. A little light-headed. Hope you get there soon.


You squeeze your way into the train, and wait. It was cold outside, but in here it's a decent temperature. You let it soak into your exposed snout, and take off the gloves. It's all you can manage in this crowd. A little extra heat will make things easier when you disembark. You wish you'd stopped to take off the coat, too.

A shame the journey isn't longer. You don't have time to soak up much heat though the layers of clothing.



You huddle in the hut. No firewood, but enough food for a week, and snow for water. Just wrap up in as many layers as you can and ride out the worst of the weather. Need to be careful, though. If the weather holds you, you could be dead in a fortnight.


Snow. No firewood, either. There's plenty of food, but in a day or so at the outside, you'll be chilled to the bone and barely conscious, no matter how many blankets you wrap up in. You won't need the food with your body slowed to a crawl, and it's most likely to turn rancid in your belly and kill you if the weather doesn't. At least it's safe in here; you can hole up and pass the days in torpor until the sun finally returns.

Summer day in Hong Kong


It's hot. Too hot to think, really. The sun beats down beautifully, but it's too hot to enjoy it. The trek to the office is going to be a nightmare. You bundle the suit into a bag, slap on sun cream and set off, with a hat and shades. In a few minutes, you're drenched in sweat, but humid as it is and with no breeze, you can't cool off. Even a five-minute halt in the shadow of the town hall doesn't help much. At least you'll soon be in a nice, air-conditioned office. As soon as you grab a shower.


It's hot; warm enough that you sleep in an extra hour (thanks, thermometer alarm clock!) and skip your morning bask. With an eye to the sun, you find shades and the biggest hat you can, and set out. At this temperature, you move quickly and easily, jogging through the crowds to get to the office bright and early. You stroll into the foyer, smooth the creases out of your suit and head on up. At this rate, you'll be able to skip your sunbreaks entirely and walk out in mid-afternoon. Ah, the joys of summer!

Spring showers


Not a bad day, really, now the rain's stopped. The sun's even come out, though it's not quite warm enough to ditch the long sleeves. Suddenly, a passing bus hits a puddle and drenches you from head to foot in cold water. Ugh! It's going to take ages to dry out. You shiver, and fold your arms to keep warm.


Not a bad day, really, now the rain's stopped. The sun's even come out, and with no wind to speak of you're taking a stroll. Suddenly, a passing bus hits a puddle and drenches you from head to foot in cold water. Ugh! You feel the cold spreading immediately, and you start stripping off, movements already getting clumsier. If you stay wet, the evaporation will sap precious heat, and you'll be spending the whole day basking to try and recover.

Oh, and because there's no particularly logical place to put this: it's important to remember, I think, that for reptiles there's no such thing as "warm clothes" (okay, barring anything with heating implants, which is actually pretty likely). There are insulators and non-insulators, and they can both be friend or enemy depending on the circumstances. A reptile in a cold environment still wants to wrap up snugly, but if they've already got cold, they need to strip down the second they get into a warm room. A reptile in a really hot environment would, confusingly, put on as many layers as possible to protect them from the heat.

Well, that was fun. Here's an idea or two for some mechanics.

As poikilotherms, they can take on the ambient temperature within reasonable bounds, and do so deliberately if they want, without suffering actual harm (though they might slow down). This has obvious applications in stealth and recon. A Monitor can take some time adapting in order to slip effortlessly past infra-red sensors, or evade searchers using heat-tracking by using a river to cool down. This ability will be affected by things like armour and large equipment. Want to infiltrate that cool-vault with the biosecurity checks? Cool yourself down to 5°C, wrap up in insulating gear and make a (very slow) trip through it. You'll be too cold to sense on camera, and your breath won't even steam. A reptile assassin could lurk undetected in the undercarriage of a plane, warming up once it's in flight and breaking out to take down a target.

Arthur also made a very fun suggestion during a chat today: chill down a reptile to torpor, pack 'em in a crate and send it through to a target as a standard delivery. It'll sail through most security checks without a problem: their metabolism will be so slow you don't even need airholes. Once they warm up inside the nice office - or, if you're cunning, once a heating charge goes off and warms them back up - they can break out and perform their mission, and maybe even post themselves right back out before anyone has time to work out what's happened.

Sticking an injured colleague in a fridge and sending them home for surgery is actually a pretty sensible tactic for reptiles; you can slow down the metabolism far enough that they won't die during the journey, as well as slowing the effects of most poisons or illnesses. It would be handy if colleagues develop insanity, too; send 'em home for therapy in a coolbag. This amount of chilling would kill most parasites, too. On the other hand, it won't do much against plain chemicals like acids, or cryophilic microbes.

Wiki snake eats mouse

So spending X rounds to acclimatise would provide a significant bonus on checks to evade such detection. Of course, depending on the background temperature, it could have some downsides...

Another fun possibility is that reptiles can actually bank body temperature to cope with later conditions. Need to adjust a malfunctioning furnace? Cool right down to nothing, then slap on protective gear and march in; you'll be in and out before the room's heat gets to you. Some mammals laying an ambush outside your igloo? Warm right up, then rush out without any of that cumbersome winter clothing; you'll be far more manoeuvrable and easily get away, or fight them off if you want. On a less dramatic angle, reptiles can avoid many of their disadvantages by planning ahead for the conditions.

As body temperature drops, they should become slower and less active. If I use an actions-per-turn system (likely), their number of actions might drop; I could also have them roll to see whether they got an action this turn. For example, in a Major-Minor system, they might alternate between these on subsequent rounds, or roll each round. There could even be an attribute roll each round to see whether they can force themselves to act more quickly.

As well as this, there would naturally be penalties on certain tasks. Anything requiring reactions would be penalised, from dodging to fighting to driving. There's even an argument that just about everything should be more difficult, since thinking should also be slower. On balance though, I think it's fair that you could do some things just as well but slower, so I'd need to think about how to implement that (perhaps just increase the duration of certain tasks).

A torpid reptile is not like an unconscious mammal. As well as losing consciousness, their entire metabolism has slowed to a standstill. They barely breathe, have no perceptible heartbeat or reflexes. Drugs, poisons and chemicals effectively do nothing, since their cells just aren't interacting with the substances - however, in some cases the chemicals will resume their effects once temperature increases, while a few will denature naturally and become harmless (or more toxic...). Only high-quality scanners will detect any nervous activity. They can't even dream, since their brains just aren't doing anything.

Within their comfortable temperature range, they can act normally.

Exposure to high temperatures or very bright light would initially be helpful, but in time can become a problem, as they can't reduce body temperature easily by themselves. While it's not strictly accurate, I think I'd allow a period of hyperactivity in the 'warm' band, when they react faster and get more actions. However, after a short period they begin to suffer heat stress and start taking whatever penalty I'd normally impose for that (damage or exhaustion - may depend on the temperature).

Temperature-band model

So first, I'm going to try just setting up a group of temperature bands, which are used to describe the reptile's body temperature. Note that this will typically not be the same as the background temperature - at least, you'd hope not, because most places aren't in the mid-30s and that's there you want to be, speaking as a lizard.

Temperature-shifting would take a certain amount of time, perhaps modified by the existing background temperature (it's much faster to defrost in a warm room than a cool one). Protective equipment would buffer the effective temperature and reduce effects on brachymetabolics. I might set this as a default 1 hour to shift one rank. I'm vaguely thinking of having a temporal scale of Turn (~10 secs), Minute, Quarter (15 mins), Hour, Half-Day (12 hours), Day, so I could decrease the time by one measure per rank of temperature difference. On this basis:

  • Shifting from Average to Cool in a Cool room takes 1 hour
  • Shifting from Average to Cool in a Freezing room takes 1 minute
  • Shifting from Average to Freezing in a Freezing room takes 76 minutes (1 minute + 1 quarter + 1 hour)
  • An insulated suit (or similar) might slow transition by one measure, or cancel out one rank of difference (which both slows and limits transition). I notice that astronauts can spacewalk for many hours without injury, so proper environment suits need to effectively prevent any temperature change.

In practice, that could well be too crunchy for the sort of game I'm thinking of, and I might be better sacrificing accuracy for simplicity.

Hypothetical brachymetabolism chart
Temperature Actions Skills Speed Daily Healing Notes
Torpid Alternate major and minor action. Incur a two-step difficulty penalty to most rolls. Decreased three steps. Reduced. After one hour without heat source, enter full torpor.
Cold Major action only. Incur a one-step difficulty penalty to most rolls. Decreased two steps. Reduced. -
Cool - Incur a one-step difficulty penalty to reaction-based rolls. Decreased one step. - -
Average - - - - -
Warm Can attempt a bonus action once per hour. Gain a one-step difficulty bonus on reaction-based rolls. Increased one step. - After 24 hours without cooling, become exhausted.
Hot - Gain a one-step difficulty bonus on most rolls. Increased one step. Increased. After one hour without cooling, become exhausted.
Scorching Reptiles cannot adapt and take heat damage as normal. - - - -

Note that the table's effects are not symmetrical. While reptiles gain some benefits from heat, they can become overheated and exhausted just like mammals, and so I didn't simply let them speed up when it's hot. Even staying in Warm temperatures for extended periods will tire them out, because they're used to cooling down overnight (and I didn't want to give them an unmitigated benefit). This table refers to the Monitor's body temperature, not the background temperature as such, so they can use shade, fans, hot-water bottles, cooling drinks and so on to regulate their temperature.

Most reptiles would enter torpor in very cold conditions, but can't survive actual freezing in reality. As yet, I'm not sure whether I want to let just any reptiles survive freezing (for cheerful pulpy roleplay purposes), or give it as a special ability to specific species and make the others take more care about their body temperatures.

Each of these temperatures would also affect mammals, but would do so differently. I'll think about that some other time. Later on I might well compress this chart down, but we'll see.

Thermal Points model

A complete alternative to this system would involve no charts at all, but instead involve managing a pool of Thermal Points. These would be increased by spending time basking, maybe having hot drinks or meals, or simply being in a warm environment and not too heavily insulated. They would be depleted by exposure to cold things, serving as a buffer between the character and the effects of the cold. As in the model above, having a small pool will impose penalties on some actions. However, there would also be a maximum capacity, and exceeding the permitted number of Thermal Points would have bad consequences for the character.

This model might make the flow of heat more salient for players, and highlight the importance of certain decisions. Chilling down to background to bypass the cameras sounds cool, but that'll leave you just one Thermal point, so you're moving slowly and have no idea when you'll next be able to warm up. A campfire isn't just comforting, it's a precious wellspring of Therms.

For symmetry, I'm thinking a pool is from 1-9 Therms, with each representing about 5°C, giving an arbitrary functional range from 5°C to 45°C. That's body temperature, remember.

The complication of this model is that you'd still need to be tracking temperature bands, to some extent, as reptiles in a warm environment won't chill to zero in the same way as in the Arctic. Also, I was initially thinking of a fun little token system where players spend tokens to avoid negative effects, but actually I'm not convinced that'd work - cooling down is a law of nature, not really something you can avoid, in the way you might spend a Luck token to avoid harm or something. I suppose you could have something like "lose a Therm or take 1d6 cold damage", with Therms lost first, but then there's also heat-replenishment and damage from excessive heat, which can't involve spending Therms. Plus, the way metabolism changes with temperature seems pretty key to me. If players don't get active control of a pool, then it's not really a token pool - what you're looking at is really a state tracker that happens to use tokens, in which case you might as well just use the tracker.

So I'm thinking all I can really take from this is some kind of temperature track on the character sheets that helps players follow their status. It's better than a hit-point-like model for something that changes a lot within a small range, I think.


Whatever system I end up with, basking needs to be catered to. Reptiles find sheltered places to just soak up the sun, and are really pretty good at it. Similarly, they use shade to help them cool down on hot days. So sun strength is another important factor. It might sound fiddly, but actually it only needs to apply when outdoors, since standard electric light puts out negligible heat. The exception, of course, will be buildings designed for reptiles, which might well blend together lighting and heating, rather than separating them as we tend to (at least nowadays with electric light).

Because there's nowhere more logical to put it, let's also note here that reptiles tend to darken when cold, and lighten when hot, which affects the amount of radiant heat they absorb. This means they're good at warming back up, and good at avoiding overheating, but I think this mostly affects basking rather than ambient temperature (clearly I need a project physicist).

Other stuff


There will, of course, be heredity-specific traits for particular characters: chameleonism, say; secondary eyelids; prehensile tails; suction pads; night vision; and all that sort of thing. But I think that really warrants its own post.

Carrier's Constraint

Strictly speaking, Carrier's constraint isn't necessarily going to apply to bipedal reptiles. But it's distinctive, at least.

This can be modelled relatively simply, if I want to use it: I just slap a relatively low limit on running time for most reptiles and amphibians. Varanids get off scot-free because they have special breath-assisting neck muscles, and crocodilians get off lightly because their locomotion is less sideways and so more efficient. Do I use this? Not sure yet.

Snake Eyes

Reptile senses are somewhat different from ours, but this varies a lot by species. Their vision often extends into the ultraviolet, which isn't actually all that helpful but might be handy for noticing security markings and so on. You could have secret Monitor marks left on places to warn other agents, which most mammals wouldn't even see.


Not everything has an obvious category, but reptiles have some pretty weird traits that could lend a lot of flavour to a game. For the most part, these won't have much mechanical effect, though.

For example, reptiles - like most animals, in fact - don't sweat. There's no guilty brow-mopping under interrogation. The cliff-dangling ally won't slip through their slippery claws. They also don't smell sweaty, of course, but some produce musks of varying strength, sometimes as a defence mechanism.

Some reptiles excrete excess salt through nasal glands.

Reptile skin-shedding tends to be much more noticeable than the tiny flakes that come off in mammals - some shed their skin in a one piece or several very large ones, and they may eat it.

Right, I reckon that's enough for one post.

1 comment:

  1. Cool!

    For what it's worth, I think a Heat Points system is more playable than something with tables (it also better matches the flavour text you used in the examples - there's a lot of talk of reptiles "gaining" and "losing" heat).