In light of the roadmap mentioning the implementation of organelle upgrades, unlocking, and endosymbiosis being targets for 0.6., let us finally create a unified concept for how these essential mechanics will work. Design for unlocking parts has been largely finalized, and organelle upgrades are a bit of a continuous and iterative process, but the general principles behind them are pretty set. Endosymbiosis still needs a big conversation for us to understand exactly how it will work. However, part of that is because endosymbiosis was waiting on the thought behind upgrades/unlocking to be settled, so I think we can finally find a solution.
It is important to consider each aspect of this unlock, upgrade, and endosymbiosis trio together because of how intertwined they will be in the player’s experience, which is why I created a dedicated post. I will essentially condense information on how unlocks and upgrades will work according to previous thought, and propose some ideas for endosymbiosis to get the conversation going. Hopefully, this holistic approach will make things more tidy and cohesive.
I’ll specifically note if something is my own suggestion so that we can differentiate between my commentary and established thought.
Questions to Ask Yourself While Reading This
There are a few questions I want you guys to consider throughout this section. I ask a few questions because I have no clear answer, and I ask a few questions because there are multiple approaches we can take, depending on what we want Thrive to play like.
How Hard Should Unlocking Organelles Be? I think prokaryotic parts should be pretty easy to unlock and I think most of you guys should agree to this. But for eukaryotic parts, should we make it so that a player can expect to unlock all potential organelles in most playthroughs, or should we make it so that a player might not expect to unlock every single potential organelle in a playthrough depending on their choices? On one hand, making it pretty easy to unlock all organelles would ensure players are able to play how they want. On the other hand, making it a bit more difficult to unlock organelles can both incentivize endosymbiosis and make your choices as a prokaryote have more weight while realistically representing evolution.
I personally think unlocking organelles should be rather straightforward, but just a bit effort-intensive. Not enough to significantly lengthen the microbe stage, but enough so that the player doesn’t have the ability to unlock every organelle rather easily if they wish to make it speedily through the stage. So that a player would eventually be able to get the specific organelles they want, but would have to invest effort to get other organelles that differ wildly from existing morphological structures in their species. But I can easily be talked off this edge.
Anaerobic Glucose Breakdown Metabolosomes require some adjustment for when we eventually add an initially anaerobic world, as they are tied to oxygen. Buckly and I thought of having it be as simple as a toggle in their Modification tab, where you can choose to supercharge your metabolism with oxygen. However, the anaerobic metabolosome still needs some input. Would we be able to get away with just having a flat rate of glucose breakdown without it being tied to any compound?
Greater Integration of Environmental Tolerances This is generally its own topic and less of a question and more of an observation, but we need to ensure that acquiring proper environmental tolerances is not a big mess for the player. We have various parts with upgrades focused on tolerances, but we run the risk of scattering mechanisms for dealing with hazards all over the editor. So that is something we should be very aware of.
We should think of unlocking prokaryotic parts and organelles differently. As Buckly mentions, unlocking prokaryotic parts should be rather easy. They aren’t as powerful as organelles, bacteria themselves are known for being able to rapidly shift metabolic strategies, and we want atleast some stability in the Microbe stage regarding what tools a player has to adapt to their environment. Unlocking organelles on the other hand should require a bit of effort, and steps into the domain of where endosymbiosis fits in.
Buckly proposed these unlock conditions, which I think are good starting points (we can adjust exact values if need be):
Unlock Conditions (Prokaryotic Parts)
Starting Parts: Rusticyanin, Chemosynthesizing Proteins, Metabolosomes (Anaerobic), Chemoreceptors.
Thylakoid: Evolve in a patch with Lux levels beyond 0%.
Nitrogenase: Evolve in a patch with less than 5% ammonia.
Oxytoxisome: Kill 5 cells OR be killed by a cell 3 times (I think toxins should also be provided at the very start to provide some mechanism of threat other cells in the beginning of the microbe stage).
Flagellum: Produce 10 more ATP than you consume OR reach a speed below 30.
Predatory Pilus: Kill 5 cells OR be killed by a cell 3 times.
Here are some proposals for parts which have yet to be added in fully. Because they are rather unique metabolic strategies, I actually do think we should make their unlocking be a bit more difficult and interesting, which can increase replayability. I think these can be improved on, so I would love suggestions.
Thermosynthase: Move into a patch with a temperature that drastically differs from your previous patch. [Likely will evolve pretty quickly, and can be an introduction to part unlocking in a tutorial]
Radiotrophic Protein: Consume another cell within range of a radioactive rock’s effect.
Bioluminiscent Protein: Successfully reproduce in either the cave or abyss patch.
Tying in Genetic Transfer - This isn’t established design and is a suggestion I came up with, but I think it slides in cohesively. Genetic transfer is very important for prokaryotic cells, allowing them to rapidly pivot metabolic strategies whenever needed. There are various methods of genetic transfer but for Thrive’s sake, I think transformation - cells finding clumps of DNA in the environment and integrating it within their own genetic information - is the only method necessary.
Perhaps we can have it so that if a player collects 3 clumps of DNA in a single life, they are able to unlock a random part. Collecting just 1 clump provides a 25% discount for your next move in the editor, and collecting 2 provides a 50% discount for your next move. This not only incentivizes exploring, but provides another failsafe for players who wish to collect all parts possible.
I will discuss the alternative method to unlocking organelles that isn’t endosymbiosis here. Much of this is my own thoughts and not pre-established thought, so it very much is up to debate.
We want two ways for unlocking organelles: endosymbiosis, representing a more involved path with more immediate rewards, or through traditional unlocks, representing a less complicated but more dragged out path. We want these two options to ensure that, based on the fact that endosymbiosis involves integrating another cell into yourself, organelles are still able to be unlocked even if your auto-evo generated selection of endosymbionts is less than ideal.
At the same time, I think we shouldn’t make this alternative to endosymbiosis so easy to do that players end up neglecting endosymbiosis 90% of the time. And I mentioned it above already, but I believe it would add a good amount of replayability if unlock conditions for organelles required some effort to achieve. I’ll show what I mean by giving you these examples:
Mitochondria: With atleast 20 ATP generated, evolve 7 times with aerobic metabolosome respiration being atleast 40% of your metabolism.
Chloroplasts: Evolve 7 times in a row with atleast 5 thylakoids in your organism.
These unlock conditions aren’t very difficult, but do require some commitment on the part of the player. And I think this makes it so that players who very clearly have a specific organelle in mind for their play style will inevitably get that organelle, but a player will have to either utilize endosymbiosis or change their morphology if they want to unlock another organelle which might not directly evolve from their current build. Again, I can be talked off this edge and I might be neglecting something, but I do think it would be a pretty fun system to see implemented.
As of now, Buckly notes that we want to stay away from “flat” upgrades as much as possible and instead rely on upgrades with tradeoffs. By flat upgrades, I mean traditional upgrades which essentially just boost stats; and by upgrades with tradeoffs, I mean upgrades which make one aspect of a part better at the cost of another aspect being diminished. So for example, modifying a flagella so that it is more resistant to currents but slower overall, making chemoreceptors detect cells but letting go of the ability to detect compounds - that sort of thing.
I personally agree with the above sentiment, though it admittedly does make how we deal with progression throughout Thrive require more thought. In my opinion, the only reason why we should consider flat upgrades is if we feel like we need to lengthen a certain stage.
There are two types of upgrades currently proposed (new more scientific terms, which I know exist, are welcome)…
Variants: Somehow changing the function of a part so that a new part arises, such as changing a spiky pilus to a straw pilus, a mitochondria to a hydrogenosome, etc.
Modification: Altering the processes of a part so that certain stats are boosted at the cost of other stats, such as increasing temperature tolerance at the cost of some metabolic efficiency, reducing weight at the cost of glucose production, etc.
We can always come up with new upgrade ideas, and I’m sure we will as we continue to flesh out the environment, but we have some baseline proposals already. We require balancing and exact numbers still, but the general idea is there. Take a look, and suggestions are welcome.
Capacity - Further devotes cytoplasm to compound storage, reducing glycolysis function in return for possessing more storage. Glucose consumption reduced by 0.006 and ATP production reduced by 1.5 in return for +4 additional storage capacity.
Enhanced Glycolysis - Reduces storage capacity but increases ATP production by 1.5 and reduces glucose consumption by 0.006.
Anaerobic/Aerobic Toggle - A switch between an anaerobic and aerobic metabolic breakdown of glucose. Anaerobic metabolosomes produce less ATP, but are more versatile in habitable ranges. Aerobic metabolosomes produce more ATP and provide tolerance to oxygen, but are dependent on the presence of oxygen and will lose anaerobic function. (Variant; will need to consult with theory to see exactly how best to approach this)
Antitoxicity - Metabolosome assists with the metabolizing of toxins at the cost of less ATP generation. Four less ATP while providing .01 toxic resistance. (Slider)
In the previous concept, antitoxicity was a perk of mitochondria, relegated to being eukaryotic. I suggest that it might better to offer anti-toxicity to prokaryotic metabolosomes since toxins are really important amongst prokaryotes. If we want the antitoxicity slider to instead be a special “power” for eukaryotes to distinguish themselves from prokaryotes however, I’m all ears.
The anaerobic/aerobic toggle will be important in the arrival of free oxygen that will happen across most early worlds when oxygenic photosynthesis appears.
Antitoxicity - Mitochondrium assists with the metabolizing of toxins at the cost of less ATP generation. 10 less ATP while providing .02 toxic resistance. (Slider)
Thermogenesis - Mitochondrium will consume extra glucose, providing heat to resist the cold in return. Will consume 0.1 more glucose (0.063 glucose at 21% oxygen) and lowers temperature tolerance by 1C (EX: Temperature range of 21C-30C becomes 20C-29C) (Slider)
Hydrogenosome - The mitochondrium will become anaerobic, allowing a wider range of habitability. However, ATP production will decrease by 50%. (Variant) Hydrogenosome - an overview | ScienceDirect Topics 1
Note that I suggest thermogenesis to be a unique eukaryotic capability in contrast to the previous post. Once again however, I’m not particularly pushing for this, it’s just a suggestion we can figure out through conversation.
Oxygenic - Photosynthesis will now split water to produce oxygen, increasing the efficiency of photosynthesis but necessitating aerobic tolerance. 8.9B: Anoxygenic Photosynthetic Bacteria - Biology LibreTexts 1.
Red Pigments - Increases photosynthetic efficiency in low-lit conditions, but decreases photosynthetic efficiency in normally-lit conditions. (Slider)
Brown Pigments - Increases tolerance to cold temperatures, but decreases tolerance to higher temperatures. (Slider)
A brief google search I did seemed to indicate that red pigments were found in deep-sea photosynthetic organisms (seaweeds and other red algae) and brown pigments were found in photosynthetic organisms closer to the poles, so I wanted to reflect this to more accurately reflect life as we know it by adding red pigments and attaching Buckly’s idea to them.
The first suggestion reflects a bit of evolutionary history, where it took a while for photosynthesis to begin splitting water, and thus, producing free oxygen. It adds a cool layer I think, but it obviously can be cut if we decide that is too much detail.
Red Pigments - Increases photosynthetic efficiency in low-lit conditions, but reduces photosynthetic efficiency in normally-lit conditions. (Slider)
Brown Pigments - Increases tolerance to cold temperatures, but decreases tolerance to higher temperatures. (Slider)
Flattened - Thylakoids within the chloroplast are flattened and more streamline, reducing mass and increasing speed but decreasing glucose generation by 10% (Slider?)
Notice the lack of an Oxygenic option, which is supposed to reflect eukaryotic photosynthesis on Earth. The option can be included here as well if you guys think it is warranted.
Increased Tolerance to Heat - Increases tolerance to heat by .5 Celsius and decreases tolerance to cold temperatures by .5. Increases total mass by .25(?). (Slider)
Sulfur Granules - Produces sulfur granules, increasing toxin resistance by 5%. Produces 10% less glucose.(Slider)
Sulfur granules have been observed in some sulfur-respiring organisms with unclear purpose as a by product of metabolism, but I took a bit of liberty in gamifying them. Open to suggestions and comments.
Increased Tolerance to Heat - Increases tolerance to heat by 1 Celsius and decreases tolerance to cold temperatures by 1 Celsius. Increases total mass by .25 (Slider)
Sulfur Granules - Produces sulfur granules, increasing toxin resistance by 10%. Produces 10% less glucose. (Slider)
Mineralization - Creates mineralized granules which add +2 Health, but reduces ATP production by 10%. (source)https://journals.asm.org/doi/10.1128/AEM.01492-06 1
Similar to the sulfur granules of the above organelles, iron granules appear in certain iron-respiring cells but their exact purpose isn’t well known, so I took some liberties in gamifying them. Again, open to comments.
Denitrification - Instead of passively generating ammonia, the nitrogenase will speed up cell processes by up to 5% depending on the amount of ammonia within the cell(?). Releases Nitrogen. Exclusively anaerobic.
I’m not 100% sure if this is solid and I just spat it out, but I want to hear thoughts. The nitrogen cycle is a very prominent component in life as we know it, both in the niches which cells take and the ecosphere’s overall health, so it feels a bit weird just having a single part of it in. I get a similar feeling with hydrogen sulfide and chemosynthesis, but of course, we should be limiting our scope in some ways.
Not so sure about this one.
Cell-Tracing - Allows the tracking of specific cell species instead of compound clouds. (Variant)
Length (Slider): Length can be adjusted, increasing the range of the player’s attacks at the expense of damage.
Something like -1 damage/+length per point in slider.
Girth (Slider): Girth can be adjusted, increasing the damage of player’s attacks at the expense of more mass. Something like +0.5damage/+0.02 per point in slider. Somewhat hidden benefit of having a wider hitbox, making it easier to block projectiles?
Straw: Turns the pilus into a hollow tube for hostile resource transfer. Pilus deals 4 less damage, but now steals 0.2 of each consumable resource from target cell on hit.
Toxic: The pilus now injects toxins into target cells. -2 damage, +2 toxic damage. Basically would allow players to bypass physical defenses in other cells by exploiting a lack in toxin resistance. Should this require toxins in storage to function?
Length - A shorter flagella decreases sprint speed but decreases the rate at which stamina depletes. A longer flagella increases sprint speed but increases the rate at which stamina depletes.
Girth - A girthier flagella decreases the effect of currents, but increases mass. A skinnier flagella decreases mass, but increases the effect of currents.
Specialization - Increases the storage for a specific compound at the cost of reducing storage for other compounds.
Parts Remaining: Radioplasts, Thermoplasts, Cilia, Slime & Toxins (Technically parts of the agent system discussion, which must be discussed). Did I miss any?
With everything laid out, let’s finally slay the dragon that is endosymbiosis. There isn’t much established thought behind it besides some conversations on my thread in the community forums, so we must brainstorm a bit. I’ll propose some basic ideas/information as a prompt, and then we’ll figure out what we want from there.
There were a lot of ideas surrounding endosymbiosis, ranging from something as simple as consuming x amount of cells with y part to full blown customization with organelle editors determining stats. I pushed heavily for the latter, but…
- Our programmers wish to maintain some modicum of mental health, and
- The point endosymbiosis serves in Thrive is essentially an unlock system with scientific flavoring, so adding a lot of complexity to it would seriously bloat game design in my opinion.
I think endosymbiosis should be a rather simple thing to do, and I think the hardest thing about it should be finding a good endosymbiont. That is, the process itself shouldn’t be hard, but the player should be encouraged to be a tiny bit selective in deciding who to integrate within themselves. We can do this by making it so that a player needs more time/resources/effort to convert a less than ideal endosymbiont to a full time organelle, but make it so that this same process is much easier with a good candidate for the part they want.
A very rough idea I have is essentially having it so that an endosymbiont candidate can be turned into different organelles based on its morphology, but having it easier to convert said candidate into a specific organelle based on its composition. For example, if a candidate has 4 metabolosomes, 3 thylakoids, and 2 chemosynthesizing proteins, you can convert that candidate into either a mitochondria, thylakoid, or chemoplast, but it would be easiest for it to become a mitochondria. And the more metabolosomes that candidate has, the easier it would be to convert it into a mitochondria.
I think that idea is reasonable, but it has some questions we must answer…
- What exactly must a player invest/do to make a endosymbiont into an organelle?
- GUI-wise, how would we present the choices a player has in converting their candidate, represent how close to becoming an organelle a candidate is, and represent the candidate itself in the editor process (considering the fact that the player at first wouldn’t be able to place their endosymbionts)?
There are two ideas I have which I feel are robust and want feedback on…
- Skip the part of endosymbiosis where a cell had to find their endosymbiont in the environment and ingest them and instead allow the player to place proto-organelles based on the cells they have ingested recently. Then players will have to spend MP on making these proto-organelles more efficient and then eventually a part of yourself. This is the easiest and most convenient way to implement endosymbiosis, but if we can, I think we should make the player have to find their candidate in the environment.
- Add an empty part button to the editor which allows players to pick one of the cells they have ingested recently as their endosymbiont candidate, and then when they do that, they will specify what organelle they are seeking to make out of this candidate. The player will then have to reproduce a certain amount of times with that candidate in their cell depending on how optimal the candidate’s morphology is to fully integrate the candidate into themselves (we will tell the player this information). So for example, if you have a really good candidate for a mitochondria, it will take two successful reproductions to get a mitochondria, while a bad candidate for a mitochondria will take six successful reproductions to be fully integrated. The player will have to find this candidate in playthroughs, and when they do, consume them. When they are consumed, instead of dying the candidate will essentially function as an organelle for that lifespan, and will only be lost upon successful reproduction or death. Reproducing will provide a population bonus for whatever AI species is your candidate.
I feel that these mechanisms are rather easy to understand once you go through it, represent a fun but very achievable challenge, provides some replayability, and provides players a safety net even if they don’t have the perfect endosymbiont. I very much prefer option 2, but if for some reason we must simplify endosymbiosis a lot, then we can settle on option 1.
We’ll want endosymbiosis to be available before the nucleus (the nucleus followed the mitochondria if you didn’t know, and I can provide a source), but we don’t want players to absolutely ignore the nucleus. I think a player without a nucleus can only complete endosymbiosis once, meaning they can only have one organelle. This will allow worried players the opportunity to make sure they have enough energy before slapping on a nucleus by seeking a powerful organelle’s help, provides replayability, and offers realism. Of course, if a player wants to skip endosymbiosis, they will reliably get their preferred organelle regardless. However, it would take much longer, and the player would have to more dramatically alter their cell’s morphology if they want a cool organelle they otherwise would get rather easily if they just went with endosymbiosis.
A long thread, but a big topic to cover. Being able to say that we have a cohesive and universal plan for how upgrades, unlocking, and endosymbiosis works will mean great news for this project. Evolution is progression, and how progression is dealt with is a backbone of game design.
Before I forget, I’d also like to note that toxins and agents haven’t been covered yet because we need to design the agent system. We will revisit them soon enough.
Reconsider the questions I asked, and let me hear input, comments, and additional thoughts.