Melee organelles: To stab or not to stab

Hey everyone!

I recently began planning on implementing melee organelles for the microbe stage, but it came to my attention that it hasn't even been decided that we will have melee organelles at all!

So lets discuss - should we or should we not have them and in what form with what purpose?

Some points to start off the discussion:

• Do some form of melee organelles actually exist in nature?
  
• Would we have an mechanism for absorbing other microbes? and if so, how would the melee organelles compliment that?
  
• What kind of restraints should there be for melee organelles? In terms of power, number of them and downsides, can any microbe use them?
  

Turns out that some bacteria do in fact have spikes (they inject toxins)

http://www.nature.com/nature/journal/v500/n7462/full/nature12545.html


I thought the microbe stage was to focus more on agents though.

Those have been discussed in detail here:

https://thrivegame.canadaboard.net/t1210-agents-discussion?highlight=agents

We will need to balance them somehow though (the spikes)

We will need a mechanism for ingesting other microbes though, I thought that was also a big part.. (It was in my prototype at least)

Perhaps, we could also allow us to "toughen" our cell membrane, so as to prevent stabbing. Eventually resulting in a full cell wall perhaps?
This way there is constant competition between those with spikes and those with armor.

I like the idea of focusing on agents better though, it is more strategic that way.

edit:
There also exists a group of viruses called bacteria-phages (something like that) that have a sharp iron spike.

I don't know much about cell biology, but it seems with the different types of attack that are coming up, we could create a rock-paper-scissors arrangement, where one type of attack is best against a second but loses to a third, etc. It's a similar system to the infantry-cavalry-artillery arrangement, both in real life and in games. And, of course, it can come up a lot in evolution.

For instance, I'd imagine agents being a good counter to spikes (or whatever is decided) as it's effectively a ranged attack versus melee, whereas spikes will beat cells whose main strategy is to engulf. In this system, engulfing cells need to beat agents in some way, although it's still basically ranged-vs-melee. As an alternative, we could have pairs of attack and defense tactics which cancel each other out. Strategy A (Def) Cancels B (Atk), C (Atk) Cancels D (Def) and so on. This way, the cells which can evolve the most cancelling tactics are likely to be the best equipped in general, and if many cells around you evolve Strategy B, you can adapt to the environment with Strategy A. And, of course, a great many of those strategies will be agents (though a universal agent neutraliser may end up being overpowered in this instance).

Good ideas!
So both from a fun and a realistic perspective we could certainly have basic melee organelles.
Tre rock paper scissors could create kind of a meta-game where organisms with one type would take over, opening the chance for another with the counter strategy to take over in popularity and ofcourse the player would have to keep up.

What about which restrictions there should be? Should a microbe have access to more than one type of strategy and should it be viable to not have anyone at all?

I agree that having melee organelles would be beneficial for gameplay and realism. As Oliveriver said, it would create very interesting situations where the player would have to either develop thick cellular walls/membrane to defend from the spikes or develop strong poisonous agents to deter the spiky microbes.

I'm not entirely sure I agree with the idea of "melee" organelles. Let me explain.

---

What is the purpose of attacking other cells in the first place? The objectives for combat I can think of are:

1) Attacking a cell to consume it and the nutrients it contains.
2) Attacking a cell that is attacking you to consume you for the nutrients you contain.

Both of these revolve around the idea of consumption, so it's clear that in this stage combat is so that you can eat to stay alive and reproduce.

Now, how and what do cells eat? A combination of free floating nutrients and other cells. A process called Phagocytosis refers to the process of cells consuming and digesting solid material, while pinocytosis refers to the process of consuming and digesting liquids. This means that a cell will go around and eat free floating proteins, amino acids, glucose molecules, etc. Thus, the first element to eating I believe should be free floating nutrients, (we don't have to include all of them, just any relevant compounds).

Eating a cell is not too different. In terms of the game, provided that the target cell is smaller than the cell doing the eating, the eating cell will absorb the smaller one. The smaller cell is ingested into the larger cell, where it is then digested by organelles inside the cell that are not simulated in the game. Thus, the second element to eating is the ingestion of smaller cells.

However, in Thrive we're throwing in the idea of cells bursting and spilling their nutrient contents into the water. Agents are the primary means why which to do this, deteriorating cell walls until they become weak enough to not be able to contain the inside pressure of the cell and they break. The victorious cell then swims through these contents and eats the nutrients the old cell had.

I'm assuming spikes would work in a similar way, damaging a cell's membrane until it bursts, spilling what it holds into the water for the player and other cells to eat. However, I don't feel this is very realistic, and I haven't been able to find any sources explaining this phenomena taking place in nature (with cells, not with bacteria). I feel like it would make the microbial combat focused around "who has the bigger spike?" and who spikes the other person first and what angle they stabbed them from. Also, as in the article Mike linked to, its not the spikes themselves that do physical damage to burst the cell, it's the toxins it injects that do the work, aka agents in Thrive. That would mean that that mode of attack is already accounted for.

To conclude, I agree with the idea of counters, such as the rock-paper-scissors model, except not for the microbe or organism stages. I endorse their use in the civilization stages, but for earlier stages, I am tentative to make evolutionary adaptations necessarily counter each other in any ordered pattern, since I feel like it restricts the dynamicism of competition between organisms in nature. I would recommend we try just implementing engulfment and damaging agents as the only means by which to attack, to begin with, and if we feel it is inadequate or boring, we can return to consider these kinds of additions then.

I need to have a proper read through the linked paper, but even if all a spike would do is inject toxins into a cell, that's still a very different form of combat to releasing a cloud of toxins and hoping your target will swim through them.

A spike would potentially require more skill, put the user at much greater risk, and be a far more efficient use of toxins. I agree that the idea of slashing another cell to bits is far from realistic, but having an alternative means of delivering a toxin is reasonable.

One possibility I've been thinking about, as a way to make the stages more distinct, is to allow spikes and other 'weapons' first in the early multi-cellular stage, so that the cell stage remains chemical warfare based, and the next stage adds a few more options.

Also, I don't think anyone meant to include a designed rock-paper-scissors mechanic in the early stages, but we should expect some cell designs to naturally counter others, and for that sort of behavior to emerge.

NickTheNick wrote:

with cells, not with bacteria

Bacteria are cells, so I'm not sure if you meant something else, should we really differentiate between RNA based and DNA based cells?

NickTheNick wrote:

we can return to consider these kinds of additions then.

Thats a fair point!

Seregon wrote:

I need to have a proper read through the linked paper, but even if all a spike would do is inject toxins into a cell, that's still a very different form of combat to releasing a cloud of toxins and hoping your target will swim through them.  

A spike would potentially require more skill, put the user at much greater risk, and be a far more efficient use of toxins.  I agree that the idea of slashing another cell to bits is far from realistic, but having an alternative means of delivering a toxin is reasonable.

One possibility I've been thinking about, as a way to make the stages more distinct, is to allow spikes and other 'weapons' first in the early multi-cellular stage, so that the cell stage remains chemical warfare based, and the next stage adds a few more options.

Also, I don't think anyone meant to include a designed rock-paper-scissors mechanic in the early stages, but we should expect some cell designs to naturally counter others, and for that sort of behavior to emerge.

It would be interesting to try out adding physical attacks in the early multicellular stage and see how that would affect gameplay, as opposed to having spikes earlier in the microbe stage. Otherwise, we could try chemical combat, and consider adding in additional combat mechanics after trying that out.

crovea wrote:

Bacteria are cells, so I'm not sure if you meant something else, should we really differentiate between RNA based and DNA based cells?

Sorry, I meant that bacteria are prokaryotic cells, and the player and the other AI will be eukaryotic.

Before we move on into the more technical points of the discussion, I just want to confirm that these are the modes of combat for the microbial stage (we can update this into the wiki too, a process we have neglected for quite some time now):

• Engulfment: Cells can engulf other cells that are smaller (have less hexes)
  
• Agent Clouds: A cloud of agents will deteriorate a cell's membrane until it bursts and the cell dies. 
  
• Predator pilus: Cells that have a small protruding pilus which can be used to inject damaging agents/toxins into other cells, which will cause those cells to burst and die.
  

Is there anything else to it?

Seems good to me!

Not sure if a discussion should be started here, but I'm curious how Engulfment should work in practise, like if you bump into a smaller microbe do you automatically start absorbing, what if you bumb into a larger one? etc.

crovea wrote:

Seems good to me!

Not sure if a discussion should be started here, but I'm curious how Engulfment should work in practise, like if you bump into a smaller microbe do you automatically start absorbing, what if you bump into a larger one? etc.

Engulfment is going to need to be pretty simplified in comparison to the actual process. The way i see it working, you're able to engulf a cell with a special organelle that allows engulfment that you can place on the peripheral hexes of your cell. The organelle will be placed as individual hexes, which add together to create one engulfment zone, which should be visually indicated by a specific color or texture. The largest total dimension of the engulfment zone determines the largest microbe you can engulf: if a microbe has a dimension larger than that of your engulfment zone, or is bigger than you in toatl area, you can't engulf it (this rule could be changed to allow engulfment to work better).
The process of engulfment involves your engulfment zone hitting another microbe of appropriate size. It is then slowly sucked into your cell.
Engulfment is a col evolutionary strategy in this case. You need to be pretty big to do it, but instead of just getting whatever compounds float out of a lysed cell, you get all of the compounds in a cell. Many cells are going to stay small because it means they have a faster generation time and therefore can grow populations faster, so you'll probably not go hungry.
One possible strategy I see coming from this is the development of sessile "siren" cells that attach themselves to the substrate and exude an agent that draws smaller cells to them. When the cells get too close, it either uses sticky flagella to snag them or just waits for them to contact its engulfment zone.

I see that you want a melee organelle model, but if we're going with engulfment would we even need a melee organelle model? It seems more like an ability than an organelle or part.

That can actually play into another play style, as a cell could have a pilum to inject a toxin or other agent into another cell to kill it or drive it off. That way it can prey on other cells that otherwise could engulf it or compete with it for food.