Photosynthesis Gameplay

So I have been working with trying to balance photosynthesis recently, and I have been finding it quite difficult to get the values in a comfortable zone where photosynthesis is viable but not to the point where it is too much so. Unlike other parts and features, photosynthesis has been incredibly tricky to balance through values alone due to how it works in the game. One particularly large issue is the difference between lux levels in the patch maps. I generally try to balance photosynthesis around it’s standard value which is 100% lux, makes sense right? This becomes problematic however, when there are neighboring zones that have values such as 200% lux that obviously doubles the power of photosynthesis. This makes balance incredibly hard to achieve, as I must basically choose between forcing players to move to 200% lux environments to sustain themselves, or letting them be able to engorge themselves on incredible amounts of glucose in said environments.
So with that said, I believe we need to either reassess the available levels of lux in patches, or to incorporate a new feature to the game to put a check on photosynthesis. that is, to finally give photosynthesizers a new obstacle to prevent them from being so overpowered.

Here are some potential features we could implement to potentially make photosynthesis less constant, and more engaging.

  1. Day/night cycle: This has been brought up by me before, so it was what came to mind most quickly. By making lux gradually increase and decrease in a cycle, photosynthesizers would need to put more focus on storage and glucose retention than simply producing. This feature has a few issues however, such as not really addressing the problem of large variations of lux between patches. Others have also previously expressed concerns that the day/night cycle would not fit in well with how time works in Thrive.

  2. Dark spots, sun spots: Instead of a day/night cycle, we could instead introduce locally varying light levels within patches. This could be as simple as patches of darkness or light in the environment that the player would need to avoid or seek; Or as complex as an ever changing gradient of light and shadow where the player would constantly seek out the brightest spots whilst avoiding the darkest. This feature could probably work better than the day/light cycle, however it could arguably make photosynthesis somewhat similar in gameplay to other features such as chemosynthesis.

  3. Photosynthesis produces heat: A more creative way of making light more of a concern, we could instead make photosynthesis potentially dangerous by producing heat as a by-product which scales with the lux levels. Too much heat and your cell could be harmed! This would force players to be much more careful about how many thylakoids or chloroplasts they carry, and make that 200% lux biome a little less enticing… However, this would require us to design a system around heat management and the workings of heat in general in Thrive. So Ultimately this option would require more work. (Not that that’s inherently a bad thing!)

I would like to hear what everyone else thinks about this, and if they have some ideas of their own on how photosynthesis could be managed.


I like these ideas. A day night could be cool for other reasons, and it would have to be implemented anyway for later stages.

One idea is that maybe you benefit from lux could be non linear, so it “falls off” past a certain level, basically a soft-cap on how helpful lux % is.


Another danger could be solar radiation, so while heat would be a danger that builds up, radiation would be immediate. We already have a concept of how it would work for radiotrophs: Radiotrophy
In this case radiation wouldn’t make any glucose, it would just harm you if your threshold is too low, if we combine that with dark and bright spots then the player can choose which spots are the best for them while avoiding those that are too bright. This mechanic would matter to non photosynthesizers too, since radiation also harms them.


I’ve been against having day/night cycle in the microbe stage before, but this could make it work, and also would make vacuoles (more) useful.

This would tie into a really old suggested feature of turning of organelles:

I personally would like the downside of photosynthesis to be weight. This is basically @tjwhale’s idea.
Pardon me for not finding a link to the original idea, but basically in real life the downside of photosynthesis (and why animals don’t do it and why plants aren’t sentient beings running around) is that you need a lot of chloroplasts to get any sensible amount of energy. So in terms of cell stage this would be that the chloroplasts would have their mass increased like 30 times making moving basically impossible. We can’t do that now but once these other features are implemented it should work: currents moving cells, and stuff spawning even when stationary, and the cell wall being a good protection against engulfing and pili, and toxins to give immobile cells a chance.
Basically my idea is that plants should be required to be actual plants in exchange for being able to do photosynthesis.

Edit: one more idea that is also probably from tjwhale: make photosynthesis so ineffective that you need more than 70% of your organelles to do photosynthesis. To also force a player to be a plant if they want to be a plant.


I’m glad to see that everyone has some good ideas regarding photosynthesis. Nobody has objected to the idea so I assume we all agree that something needs to be done to help it more engaging. In particular I would like to see what the theorists such as @Phrenotopian have to say about the idea, as people on the community discord were quick to inform me that my and others ideas were not necessarily realistic. I don’t expect to be entirely realistic but I would like to get as close to reality as possible while still keeping Thrive entertaining as a game.

That makes alot of sense to me, as 100% efficiency in life is pretty much unheard of, everything has diminishing returns. Something like this is also probably an easier thing to implement compared to totally new systems.

I would love to see radiation and radiotrophs implemented, it’s such a unique feature but still needs quite a bit of discussion about it’s full extent as it will be a danger to more than just photosynthesizers. We’ll have to resume that discussion sometime!

Weight makes a lot of sense, but I am rather hesitant about preventing a player from properly moving in a stage where there’s not really much else to do but swim about in search of nutrients yet. If there were systems to manage and things to do while your cell drifted about it could be fun in it’s own way. Making them a little heavier could present the same problem, but atleast players could still move a little?

I could give that a try, though it’ll be pretty tough to avoid having to make photosynthesis great again, again.

Everyone’s got some good ideas that can probably each work fine. A few will probably be implemented as their own features and functions sometime in the future regardless, but we aught to decide on what would be the most preferred method of enhancing phototrophic gameplay at the moment. Any preferences? We can always make a poll for the community or the likes if we have trouble.

I’m not dismissive of these ideas regarding photosynthesis. Realism is fun, but there should also be some leeway for being innovative i.e. create speculative evolution. It should also not be too loose and easy, because everything comes at a price, but I can see your challenges. I need to sink my teeth into the subject more to come with something more qualified, but here are a few things from the top of my head:

  1. I’m actually a bit puzzled as to why light is expressed in percentages and not e.g. absolute units like lux or watt. Also, 200% lux makes no sense to me, because percentages over 100% indicate growth. So, I suggest we first of all go over to absolute values.
  2. Using absolute values, it actually becomes interesting, because then you can vary light levels depending on not only depth, but also day/night cycles, as suggested. Sunny spots would be fine, but it would make even more sense with e.g. clouds or cloudy days.
  3. Another thought I had, already mentioned by Nokk, I see, is capping. Simply put a cap to the amount of energy (ATP) that can be harvested from certain light levels. In other words: Even if there’s more than plenty of light, you won’t get more energy out of it, due to physical constraints that are imposed on photosynthesis.
  4. I’m not sure overheating is an actual problem IRL for photosynthesizers, but I could be wrong.
  5. Also I never heard of chloroplasts adding too much weight, but again: I could have missed that information.
  6. At different depths, different spectra of light dominate, which is why e.g. red algae dominate at lower depths, and green algae in the highest levels. Maybe also something to take along. If you want to thrive in lower light levels, you need different kinds of pigments.
  7. Something even more fun and competitive is shading. Now the current gameplay appears to be top-down, but we could impose it to be sideways, meaning the top half of the screen is above. And that means that cells at that level block light to some degree, making it an advantage to struggle to get to the higher levels. This is also akin land plants growing to get the most light, while those left in the shadows have fewer resources.
  8. Now that I’m at it: I had another idea, as sessile species haven’t really been considered, because that seems boring. However, species that can stack their static cells into growth forms that branch out throughout the water could provide interesting gameplay for even non-swimming species. This remind me a bit of several mobile apps like “Tentacle Wars” and “Auralux”.
  9. For benthic zones, we could even provide solid growth substrates, i.e. rocks and sand for sessile species to grow and expand from.

OK, those are some pretty wild ideas already, so let me know what you think.

EDIT: I just realized I opened the door for “Microbial Mats”! :smile:


Microbial mats… Actually a wonderful idea now that you mention it. Whenever plant gameplay is brought up among the community, the most common perception is that it will take the form of a more strategic and base-building-like gameplay since you will be immobile. Of course, this was only in regards to later stages when you are a full blown plant rather than a single cell. But this idea right here however, seems like the perfect way to introduce players to that style of play! I imagine it would be a sort of gateway into the multicelluar stage as well.
But of course, I would not want to deprive players of the ability to be a free floating photosynthetic protist either.

That being said I like your ideas, it’s clear there’s a thousand and one ways we could go about introducing new features to photosynthesis. Now all we really need to do is decide on what we want to go for.

1 Like

Thanks, Buckly and now that I mentioned benthic sand: Imagine burrowing and digging organisms! :star_struck:

I know these are crazy ideas, when Thrive has been stuck at the cell stage for years, but implementing even a few of these would make for a unique and extremely exciting gameplay with loads of different possibilities!

1 Like

I think we all have to decide what direction the game will take. Photosintetic-based life is quite boring in terms of gameplay, because in real life as a plant or an algae you just stay here and, well, live with the sun. Of course in a videogame you don’t want to just stare at the sun, so we just have to decide how much “fictional” the game would be.
In technical terms, radiation levels aren’t this big deal if you stay underwater, that’s a very efficient shield against UV. The cloudy feature is interesting in term of gameplay, but in real life it doesn’t change much a plant’s life (unless you have dense clouds continuously for months). As @Phrenotopian said, i never heard about overheating in vegetables cells, because the photosyntesis is a chemical reaction that absorb energy, it doesn’t dissipate it as heat.
A good way to make more challenging to be a plant could be implement more the predators. If you are basically a bag full of glucose, there are a lot of bad guys that want it from you. Choosing to be fully photosintetic require to be large and slow, and so you need to find all the way you could to defend yourself from other heterotrophic organisms. Maybe if other cells have a very simple AI that chasing you more if you contain more glucose could be a good feature for photosintetic and chemosintetic gameplay as well.

1 Like

Thank you theorists for pointing out what concepts follow reality more closely, and everyone for their wonderful ideas. After all of this discussion I believe I can narrow our ideas down to what will likely be more preferable for a fun but somewhat accurate representation of reality.

Option 1 is cyclical light, such as the day/night cycle (Or maybe seasonal changes?). This feature would require a little extra discussion on how exactly it will be implemented in a way that it will fit into the game properly, but is otherwise pretty straight forward.

Option 2: Giving photosynthesis diminishing returns, or capping it as suggested by Nokk and Phenotopian. There are several ways we could go about this, depending on if we decide to change lux from a percentage to a basic value or if we rebalance the patches to no longer have lux above 100%. But overall I think this is something we can try alongside the other options with little difficulty.

Option 3: Make pigmentation effect photosynthesis rates, as suggested by Phrenotopian. This would give photosynthesis additional depth by encouraging players to specialize and adapt to specific environments instead of each environment being identical aside from lux values. It would require a bit of discussion and research however, such as how we want to handle pigmentation (Would membrane color matter or would it be thylakoid only?), costs (Should some pigments be costlier than others?, should changing cell color cost MP?), and values.

These three options are not by any means mutually exclusive, I believe they could each work effectively for our means so don’t assume you need to choose a single option from the list. Unless anyone objects or has further ideas, I believe that these may be our best options for the game.
So from here, I would like to discuss these options in further detail, as well as ensure that everyone agrees with my choice of options.

1 Like

These three options are very interesting, as we already said before.

Option 1 could be interesting, in my idea in seasonal way (maybe introducing some randomized climate change, simulating various geological eras), because day/night would be very confusing about time of evolution: my cell change in a week? That could give wrong information to the player.

Option 2 could be great: it’s correct and gives more depth in terms of gameplay. I absolutely agree to gives light an absolute value instead of percentage and to put a soft cap in terms of efficiency: the more photosynthetic organels you have, the less they are efficient.

Option 3 would make the photosynthetic gameplay much more complicated, i don’t know if it would still remains funny. I think that giving the player the chance to choose among all the possible colors of pigmentation could be too much. Maybe putting different organels could be better, in this way the player could be more strategical in the implementation of photosynthesis than now, where you simply run through patches to reach 100% lux and then spam out thylakoids. Giving the chance to choose the different wave length to absorb could be interesting if it doesn’t become frustrating.
Maybe could be a good idea to give a discount on the evolution costs when you change photosynthetic organels, otherwise when you change patch you could find a lot of your organels useless.

1 Like

Thank you for your input Smugmoss, option 3 is for sure complex in application, but I personally feel that if done right it could make photosynthesis much more engaging. Option 1 is also something I believe would be a great feature, but before we discuss it any more I believe focusing on Option 2 would be in our best interest, as it effectively lays down the foundation of how the other mechanics will operate in turn.

So, I have come up with an idea on how light levels will be calculated, displayed to the player, and function in general. So here goes!
First of all, the world will have an overall lux amount. This lux amount will be determined by the type of star the player’s world will have. Let’s say that the player’s star generates 100 lux (A pretty dim star). This amount will be the base amount that is later modified depending on where the player is in the world.
Next, the lux level will be modified by a percentage. This percentage symbolizes how much light ultimately reaches the player in their current patch or locations, with 100% lux obviously being all of the light. Let’s use the ice shelf patch as an example here. It currently has 50% lux (Which we will probably need to change alongside the light system changes). With 100 lux being filtered into the ice shelf, only 50 lux makes it to the player for photosynthesis. This change lays the groundwork for any further changes and factors we might want to include into the game, such as atmospheric light filtering or organelle efficiency.

So Tldr; Patches will have a hidden percentage value that determines how much light reaches the player in that patch from the planet’s star. 100 lux --> 50% lux patch --> patch has 50 lux.

Edit: I forgot to mention the most important part; How this effects photosynthesis! With the lux values now being a solid number instead of a percentage, photosynthesis will have to work differently as well. As of now, my idea is that photosynthesis will have a maximum and minimum lux requirement. Not enough lux and you will produce nothing, while passing the maximum value will produce no further glucose.

1 Like