Beginning Concepts on The Multicellular Stage

[Rathalos]

@Deus

What signified “multicellular” as opposed to “unicellular colonial”? A.k.a, how does progression look from stage to stage?

From what I have read recently:

• Cell differentiation
• A defined body plan
• Anatomical structures that do not exist in individual cells

And maybe, from an older article I did not yet summarise:

• Some cells not being able to collect their own food, instead being fully reliant on other cells closer to the exterior.

All three of those first once do absolutely require the multicellular editor, so I guess that’s fitting. Though I suppose “defined body plan” happens automatically when you unlock the editor at all, while cell differentiation is a conscious choice afterwards.

Two other related things:

1. Directly sharing resources between cells is something that some but not all colonies do, while true multicellular organisms obviously always do. So this is a clear candidate for a prerequisite step before transition to multicellular.
2. Something that pretty much all the forms of more complex multicellular life have are cell types specifically for reproduction, which I will inaccurately call germ cells here. This may or may not be a good candidate for advancement to macroscopic.

@Deus

It basically is, yes - with this concept, as the size of your colony increases, so does the cost associated with binding agents. We can just assign that as size-related costs associated with colony activity, but since this would apply to unicellular organisms which can exhibit colonial behavior as well, it might be difficult to present that as its own thing.

I realize that problem would still be present with binding agent costs as well; but if we include intracellular size-related costs as well, could that lead to some confusion or crowding for the player to look at? Atleast with binding agents, players pretty clearly associate that with multicellular activity.

Hmmm, I was thinking that having it hidden away in the tooltip of an organelle that by definition players may have little reason to look at after placing it might be a problem. With having it being its own very obvious UI element being the better option then.

@Deus

This would apply to unicellular colonies in accordance to the progression from 1st to 2nd stage concept, and communicating that cost could be difficult.

Perhaps one way to approach it is to have binding agent costs act a bit differently for Microbe Stage organisms, where each additional bond adds a flat cost instead of one that might be more dynamic for Multicellular colonies. So the initial osmoregulation cost of a binding agent is 5 - binding with another organism adds another 5, another bind adds another 5, etc. So with this math, the player could somewhat intuitively figure out that a colony of 5 would require atleast a 25 ATP margin to fly.

To be honest, this is starting to concern me a bit with potentially adding a large cost on an activity that actually has fairly little benefit right now.

@Deus

That is a good point about whether or not the penalty grows with a multicellular organism or if it is just applied from birth to every cell. I think it would be best to just have it be applied from the beginning for multicellular organisms so that your initially productive cells don’t just start dying after a certain part of your growth. Though that does bring up questions related to player intuitiveness.

That would indeed be a reason to have the penalty be constant during the generation, even though it probably does not make logical sense.

Right, I am wondering if we can think of a type of penalty for having too many cells that is clearly detrimental, but not lethal in that way. We might need a hard cap on the number of cells anyway to ensure performance from what I remember.

@Deus

I think that’s very valid, I just wonder how intuitive it would appear to the player.

Good point also. But to clarify what I am thinking: similar to your macroscopic editor concept, there’s a list of statistics for the whole organism off to the side somewhere stating among other things: organism size x cells, causing -y efficiency in all processes. Or something like that.

@Deus

The “eh here’s some jargon” explanation

I think what Bird is saying here makes some sense, but more in the sense of the types of things our organism needs to evolve in order overcome the problems I mentioned in the previous paragraph, in order to become macroscopic.

@Deus

That could also work, but I do think about how exactly that would work if adding this part results in the stage transition. Do you just build up to this expensive part, and if you reproduce x amount of times with it, you become multicellular?

To be honest I was originally thinking here about stage transitions be directly caused by something like placing an organelle, or in this case an upgrade on the binding agent, or something along those lines.

Just to give an example (that is of course itself not a good idea): imagine placing the binding agent and leaving the editor didn’t unlock the ability to make colonies but just directly sent you into the multicellular editor. Sure you could ask “what is the feature of this organelle?” and the answer would be “the whole next stage”.

@Deus

what would incentivize a player to actually utilize binding agents if the placement of a part is the definitive source of transition, and not action related to the agents?

A decent question, but I think it also goes for any other organism feature you yourself secretly only add because of what you want to evolve it into later. (like bony fins, because you need to turn them into limbs later on). Maybe the answer should be the same: if you have them, you should want to use them because their function, in itself, is too useful to ignore.

@Deus

I definitely think the current stage transition is flawed in that it is very easy to fulfill once you place down a binding agent, but I atleast do like how it forces you to mirror an action or behavior fundamental to the stage you are trying to get to.

But I do actually also like the idea of requiring some gameplay action to transition. Maybe this could use organelle unlocks or something similar?

By the way, if we include the multicellular stage starting with you already having a design of an unspecialised colony; I do also like the idea of making you play one generation growing into that colony, before you get to enter the editor and edit it/start specialising cells.

@Deus

I think Size-Related Costs should be their own “box” in the ATP bars for Organism Statistics, if that makes sense. Another interpretation involves just scaling osmoregulation costs, but I’m not really in favor of that. I think it is important that players understand exactly how much their size is costing them, and if that is bunched with osmoregulation, that isn’t very intuitive: what part of osmoregulation is just because of my parts, and what part is because of my size?

I think this would be a good approach. My only concern here (and with things I suggested myself before) is how to bridge from “organism-level statistics” to ATP costs, which are at the cell level always.

@Deus

I also have heard that, and very interesting - perhaps cells need a bigger size gap to engulf cells in a colony. This would incentivize the development of cell functions and abilities as opposed to just relying on engulfment when engaging with other colonies, mirroring the development of more complex adaptations. Like you mention though, it might be difficult to implement.

I do think going for “you need to be large enough that you can could engulf the whole colony in one go” would be the simpler option here. Though I do realise that will mean “you cannot engulf cells in colonies” most of the time (outside extreme cases or prokaryote colonies), that’s not necessarily a bad thing? As you said, it makes you look for more advanced ways to fight colonies.

As for implementation: I just realised that the game must be keeping track of colony size already (because there’s a counter for it). So quite possibly this is a case of simply making engulfment check for if the engulfer is large enough to engulf target cell size x target colony size.

@Deus

• Since we don’t really have some sort of “linear upgrade” system for any other part of the game, this could stray too far away from our core design principles.

Hmmm, I was only concerned about if the system/UI implementation would be manageable. I figured if the upgrades still had their own cost/downside, so that they’re not worth it for every species, that would still be in keeping with Thrive design principles.

@Deus

• These could perhaps be represented as parts - but that would be a large number of parts for a very specific phase of the game, which clutters the editor and could confuse players.

Very true. I would at max go for having one more part: an “exterior organelle” (so like flagella, etc.) that forms a connection with other cells for the “sharing compounds” part of the colony behaviour.

@Deus

Perhaps these bonuses could be applied to unique parts in the Multicellular Stage instead of a mandatory bunch of parts you must place on a unicellular organism to progress? Through either things you place on your cell, or extracellular parts as you mention.

Well, the random examples I gave have things that I would consider should be in place before you go into the multicellular stage proper (especially the compound sharing part. Once you reach that point the focus should really be on changing the colony into a proper organism (rather than “getting better bonuses from colonies”.

@Deus

That is a good point. Perhaps sexual reproduction is tied to the placement of a part on either your colony or your cell (sexual reproduction did evolve with eukaryotes afterall), and your growth strategy is something different. Or it could just be a toggle in a sort of reproduction strategy menu, such as the basic one we already have which only lets you select budding.

I think this indeed makes the most sense. Quickly reading through the existing literature, I think it could be made a feature of the nucleus itself, or even an upgrade to it.

The multicellular stage aspect would be somehow making a specialised cell type for this purpose. (which as I said before, could even be a requirement for progression).

@Deus

I do wonder if we could atleast have it so that certain parts in a cell disappear at different life cycles, since if any stage could have a pretty dedicated breakdown of a life cycle, it would be this one. Though like you said, it entirely depends on whether or not this feature could be demonstrated intuitively, and if it is worth the labor.

I guess we’ll have to ask hhyyrylainen about the feasibility of this later on. But I am also concerned about whether this is too in-depth for typical players to handle. Visualising it could also be difficult unless we have separate screens for the growth stages.

On a similar note: maybe we can have new cells growing in the organism as stem cells before they turn into their proper type?

@Deus

• I wonder how frequently membranes change within eukaryotic species as opposed to multicellular species - could membrane switching in eukaryotes to the extent we have it in the Microbe Stage be similarly not based on sound science?

Well, plants and fungi both evolved a cell wall compared to animals, so I guess that’s more frequent?

@Deus

• I agree, but that could also lead to some frustration on the player’s behalf if they realize that they are restricted upon entering the Multicellular Stage and beyond. My concepts for the Macroscopic Editor does have the integumentary system be binding in some cases, but atleast with that, there’s a possibility for change if you “de-evolve” certain parts. For something as fundamental as a stage transition, I wonder how possible it would be to offer that “revert-point”.

Good point here. Then maybe we can borrow that idea from the macroscopic concept also? We keep the “cell membrane type must be the same across the organism”, but only lock it completely as long as you have a part somewhere that requires your current membrane.

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By the way, I was thinking of how we can potentially have “muscles” in cells that have cell walls (because otherwise everything that does not have a “fluid membrane” would be pretty much not worth playing in macroscopic and beyond). And I remembered that plants do “abuse” turgor pressure to move body parts around, and apparently fungi use it too. In principle, the potential is there as long as you have a semi-flexible cell wall.

So that could be a cool starting difference between types: if you don’t have a cell wall, you can unlock myofibrils, and if you do you can unlock for example a membrane organelle that turns the tissue into a “turgor muscle“. With some statistical differences between the two.

@Deus

That is very interesting - perhaps more rigid membranes increase the size discrepancy needed for engulfing things, and fluid membranes do the opposite.

I don’t really like messing with the size ratio unless we add an ability to easily confirm whether you can engulf something without trying it. But that would work with rigidity slider, while an on/off on engulfment would require a different type of toggle. (like a new “type” of cell membrane that you can use as an alternative to your normal cell membrane in the multicellular stage for specific cell types).

@Deus

I think a good approach here would be first to create a list of some potential abilities we can represent in the Multicellular Stage (like you mentioned, some examples of shelling, mesoglea, utilizing very powerful currents to engulf, etc.)

Then from these abilities, we can discuss whether or not these parts can be fit into traditional part placement, or if it would require something like extracellular parts. Again, I’m not necessarily against this concept, just wondering if it is a layer of complexity that should be added in this way. If we come up with abilities that would really benefit from this interpretation, then its case is much stronger.

Good idea, we can check whether such a system would even be necessary at all.

I am also thinking of an alternative where these kind of non-cell structures are just automatically placed around cells that have the appropriate cell parts.