I haven’t been able to sit down and play the Multicellular Stage recently because of my studies. That will change by the end of this month, but in the mean time and whenever I thought of Thrive (everyday), I still have been doodling things down related to the Macroscopic Stage.
There were a few lingering questions from the comprehensive editor concept, so this is more of a focus session on two topics: constraint relationship with environmental factors - which covers early game balancing and can have strong effects on world variability - and how movement on land can work - an important remaining question-mark for the concept.
ENVIRONMENTAL TOLERANCES AND CONSTRAINTS
Environmental factors will have a much stronger anatomical impact on your organism than in the microscopic stages, with larger animals having to rely on structure as opposed to biochemistry to maintain homeostasis across complex cell types.
Environmental tolerances will first be affected by constraint stats. I focused primarily on temperature since adaptations there are the most straight forward when it comes to structure.
Mass
- More Mass increases Cold Tolerance, Decreases Heat Tolerance.
- Less Mass increases Heat Tolerance, Decreases Cold Tolerance.
Higher mass organisms (objects in general) absorb more heat, and maintain their temperature longer than smaller mass organisms. Meanwhile, smaller organisms absorb less heat, and heat exchange occurs at a much faster rate - leaving smaller organisms vulnerable to rapid heat loss.
SA:V
- A Higher SA:V Ratio Increases Heat Tolerance, Decreases Cold Tolerance.
- A Lower SA:V Ratio Increases Cold Tolerance, Decreases Heat Tolerance.
A higher SA:V ratio indicates the presence of thinner structures on the organism. Thinner structures are much more sensitive to colder environments due to a closer exposure of internal structures to the environment - a thinner item is more likely to freeze thoroughly and snap. However, this also increases exchange rate with the environment, which thus means that organisms are much better able to cool off instead of retaining heat.
Key examples of surface area adaptations to heat can be seen when comparing mammoths and modern African elephants. African elephants have expanded ears which they fan, allowing them to cool themselves off. On the other hand, mammoths deal with frigid environments and harsh winds, so having such a large ear can risk organ damage and frost-bite, as well as rapid heat loss.
A Dimetrodon, who’s sail might have been useful in regulating temperatures.
A desert mouse who’s ears, along with increasing sensory capabilities, allows better temperature regulation.
Scaling Concerns
One problem that can come up is that since the player starts as a puny macroscopic animal, they will inherently have a really high SA:V, and a really low mass.
- A feature to consider is to have environmental tolerance ranges shrink as mass increases, thus making it a problem that larger, more “advanced” animals will have to deal with. This can atleast be somewhat justified theoretically - smaller organisms can rely more on biochemical processes and agents, such as anti-freeze, since there is just less cellular matter to cover. Larger, more complex organisms have more biomass to cover and oftentimes more diverse types of cells, so it isn’t as easy to cover everything with an agent.
- Otherwise, influencing environmental tolerance range with other progression markers can be an option.
- Mass effects and SA:V effects counter-act each other. Low mass means less heat tolerance while high SA:V means high heat tolerance, and v.v for cold tolerance.
- In general, scaling factor will significantly reduce as a player progresses through the stage. 1 foot vs 1 cm is a scaling factor of roughly 30. 5 foot vs. 60 foot is a scaling factor of 6. That should reduce discrepancies.
- Otherwise, some sort of cap can be introduced - anything beyond an SA:V ratio of 10 will tip the scale 7 degrees celsius towards warmth, anything below mass of 50 grams will decrease heat tolerance by at most 5 degrees celsius, etc.
Effects & Moderation
- Warmer worlds will likely have smaller organisms with higher surface-area on average. Colder worlds will likely have larger organisms with lower surface-area on average. This can easily have cascading effects considering how strongly tied to all stats constraints are.
- Larger organisms will generally have to utilize constraint-related environmental tolerance tricks, such as expanding/shrinking surface area, considering the effect of more/less massive adaptations, etc. Smaller organisms will have some more wiggle room.
- The effect of constraints on environmental tolerances should be decently strong, but not totally influential to the point that other adaptations aren’t influential. A hypothetical organism increasing size from 5 feet long to 10 feet long shouldn’t go from the desert to the tundras just because of their size. Similarly, massive organisms should still be playable in cold environments with proper adaptations.
DEEP DIVE ON GROUND MOVEMENT AND INTERACTION WITH CONSTRAINTS
The original concept regarding stats such as speed and their interaction with leg structure was pretty broad. I initially left a broad suggestion along the lines of “less mass on limb & higher streamline = faster”, but as Rathalos points out, that’s pretty reductive - many extremely fast animals have a ton of muscle mass on their limbs.
Movement on Land
I think we can think of two types of movement on land:
- Standard Movement. Just normal movement along a flat environment.
- “Rough Terrain Movement”, indicating movement through a medium that an organism isn’t suited for. Right now, I think there is a case for just two big groups of rough terrain:
- Boggish/Swampy/Wading Movement - Movement around shallow water. This is important for Thrive because of the progression from living in water to living on land.
- Slope Movement - Movement along terrain which is uneven, such as hilly, mountainous, rugged terrain.
There doesn’t really have to be too much difference between the two “rough terrains” - all that matters is that it slows down base movement.
What Affects Land Mobility?
Speed will first of all be heavily influenced by mass of the body, not just the limb itself.
- More massive organisms will generally be less fast and less agile.
- Less massive organisms will generally be faster and more agile.
Leg Structure
On land, longer limbs will decrease streamline measurement, while shorter limbs will increase streamline measurement. This can be approximated by the distance between the ground and the torso for a legged organism, since an animal that is taller will naturally have longer limbs. Please note that “streamline” here means in relation to various mediums, not necessarily to air - streamline measure to air becomes the primary focus if wings are on your organism, which will alter the relationship between movement stats and constraints.
More Streamlined Land Animals
- Have less stamina.
- Are more capable at maneuvering through rough terrain, swimming, and burrowing.
- Are more influenced by the effect of mass on movement speed.
Less Streamlined Land Animals
- Have more stamina.
- Are less capable at maneuvering through rough terrain, swimming, and burrowing.
- Are less influenced by the effect of mass on movement speed.
This is meant to proximately represent more “squatted”, reptilian leg structures, vs more “upright”, “active” leg structures. More squatted organisms are capable of intense spurts of athleticism and are generally more maneuverable in harsh conditions, but are less efficient overall due to their musculature having to be more involved. As such, they tend to have a tougher time moving on land if they become larger. An “extreme example are crocodilians - extremely well-adapted for swimming and movement on uneven footing, but rather uncomfortable on land.
More upright animals are more efficient movement wise because their bone structure takes more of the energy and force needed to propel themselves. As such, larger organisms tend to have more upright leg structures to maintain movement efficiency. However, longer limbs can be more gauntly. An extreme example are giraffes - among the fastest animals in Africa despite their size, but extremely delicate to uneven terrain.
Extremities
Extremities - in this case, feet - are extremely influential in affecting movement of land organisms. One of the most important stats for a foot is SA:V ratio.
Less SA:V in your foot, which leverages force through a more focused part of contact with the ground, means:
- More base movement speed and agility.
- Base speed and agility is more influenced by mass.
- Less movement speed on rough terrain.
- Slightly less stamina.
SA:V of a foot can be decreased by decreasing digit count, making digits more “stubby”, etc.
Higher SA:V in your foot, spreading force through more area in contact with the ground, means:
- Less base movement speed and agility.
- Base movement speed and agility is less influenced by mass.
- More movement speed on rough terrain.
SA:V of a foot can be increased with a bigger digit count, more flattened digits/feet, etc.
Extremity Choice
Different feet will influence both the constraint stat and how the constraint stat affects secondary stats. For example:
- Hoofed = Maximal reduction of SA:V. Strong boost to base movement, and makes mass less impactful on base speed.
- Webbing = Increases SA:V. SA:V ratio more strongly boosts movement speed in water. SA:V boosts elevation movement less.
- Thumb = Allows grasping with foot, with higher SA:V ratio indicating greater ability to manipulate objects. SA:V’s bonus speed against mass is strongly diminished.
- Flattened Claw = Adds a flattened claw to the digit, slightly increasing SA:V. Bonus speed against mass is improved, allowing larger organisms to be faster.
- “Cleated” Claws = Claws are adapted for traction against flat ground, akin to a cheetah. Significant boost to speed based on reduced SA:V, but stamina is more significantly depleted by reduced SA:V.
Note that these extremity choices both influence the constraint and alter the bonuses attached to the constraints. This is to represent two things:
- The extremity itself generally is better at something than other extremities. Even if you have digits with extremely low SA:V, a cleated claw will benefit you more than a flat claw.
- The anatomy of the underlying digit is still extremely important. The claw of a cheetah is important, but it only makes sense alongside with the rest of a cheetah’s anatomy.