Building a food chain in Evolution: The Oceans

octopus-600 It might be hard to make those tentacles for the production version of the game, but this is the first player marker we’re using for playtesting.

Two weeks ago we announced the development of Evolution: The Oceans, the next game in North Star Games’ line of Evolution themed games. Today we get into the (sea)weeds about the game itself (there will be poorly executed water puns throughout these posts). First, a caveat:

Evolution: The Oceans is under active development. We’ve got a long way to go and nothing is sacred. Sometimes you have to kill your darlings and we’re natural born killers. 


Parenthetically, this project has given me an enormous appreciation for killer whales. They’re giant genius murder dolphins in tuxedos. Here are three killer whales catching a seal, brilliantly:


Anyway. One of virtue of working on a game system several times over is you come to know it deeply. Its strengths and weaknesses, its points of flexibility and rigidity. Having participated in the development of 4 Evolution games (Evolution 2nd Edition, Flight, Climate and The Beginning), we now have that kind of perspective.

That’s important, because Evolution: The Oceans will be a departure, and our experience provides a much-needed roadmap.

Two reasons for this departure:

  • previous Evolution games have been on land, and marine ecosystems work differently. We can’t honor the theme without significantly changing the system (theme is the first consideration in every design decision for these games).
  • after several Evolution releases, we’re at risk of going stale. We don’t want to create Munchkin Evolution: Star Wars Edition, if you smell what I’m stepping in. Now’s the time to put what we’ve learned into the service of something new.

Today we describe the one feature that’s been in The Oceans from the beginning. It’s the kernel from which the rest of the design has grown. It’s not the most drastic change (we’ll talk about that later), but it was the spark.

In terrestrial Evolution, when you create a species, it’s an herbivore by default and it eats plants at the watering hole:

watering-hole The Watering Hole

To turn a species into a predator, you have to give your species a special Carnivore trait. It makes being a predator a special thing.

FullSizeRender The Carnivore card

But it wouldn’t make sense in the oceans. In the oceans, most non-tiny animals eat flesh, especially most of the species you know. Sharks, dolphins, killer whales, rays, anemones, starfish, octopuses, squid, seals, walrus, lobsters, crabs, most eels, and most fish eat flesh. About the only non-tiny creatures which don’t are filter-feeders (like some whales, some fish, and mollusks, which eat plankton) and the odd plant-eating fish or mammal.

Herbivores, at least as we think of them on land, are rare in the oceans because plants aren’t the base of the food chain. Plankton is. Plankton is made of a mix of many different tiny species, both plant and animal, floating around in massive quantities in the ocean’s upper layers (the deep oceans are mostly desert). A rough shorthand way to think of plankton is “all the tiny floating stuff”.

When we first started thinking about the specifics of a standalone game about marine ecosystems more than a year ago, our first thought was about how to embody this food chain in game rules. The idea we had then has remained in every iteration of the game since.

Here’s how it works:

  • The base of the food chain is plankton. You get it from the reef. This works just like plants and the watering hole work in regular Evolution.
  • If a species’ body size is 1, that species is a plankton eater.
  • If a species’ body size is greater than 1, that species is a predator, unless it has a trait that changes that.
  • Right now, the only trait that allows you to eat plankton at larger body sizes is Filter Feeder, which makes you to eat plankton at any body size.

So there are a lot of predators. Here’s how they work:

In real life, Ocean predators generally only eat prey in a limited range of body sizes. The limit is set by two factors, one which limits maximum prey size, the other which limits minimum prey size

First, most Ocean predators eat their prey whole, in one gulp. Since it’s hard to swallow something larger than oneself, Ocean predators limit their meals to critters smaller than themselves. That sets the maximum prey size. Eat something too big and you end up like this:

fish choke

The second factor is energy. It takes energy to catch prey. Because most predators fail a lot when hunting (they’re generally only successful about 10% of the time), they need to make sure each hunt yields a big payoff.  If a big shark can only find minnows, the energy spent chasing them won’t be replaced by the energy they provide. So predators don’t eat things too much smaller than themselves, and all their predatory machinery reflects that. A shark mouth isn’t designed to enjoy a minnow. It’s designed to terrorize seals.

seal murder.gif

Because body-size is explicitly represented in the Evolution games, these dynamics are easy to implement! In The Oceans, a predator can only attack a species which one or two body sizes smaller. There are obviously exceptions: huge animals that eat tiny ones, or small animals that eat big ones. But that’s what traits are for and thankfully, Evolution has traits.

There’s a lovely parallel here between the structure of the game and the nature of biology itself. Biology is about finding patterns in living things and making generalizations, but also cataloguing the ways the generalizations are wrong, the ways species deviate from “the rules”.  Whales eat plankton, piranhas team up to tear apart bigger animals, parasites eat from the inside out, etc.

The core rules of Evolution embody the generalizations, and the traits embody the deviations. The structure of the game mirrors the structure of biological theory. Dope.

So in the game and in real ocean ecosystems, one way to escape predation is to be too small. We’ve strengthened this defense further by allowing species’ body size to evolve up or down during the game, which has the nice benefit of being more true to nature than the original game (which only allowed species to get bigger).

It also creates new, realistic tactical dilemmas. I may want to remain size 3 so I can eat a size 1 species, but if I do, I remain vulnerable to that size 4 species over there. What do I do? It’s a true food chain. 

We’re excited about this, first because it makes the game feel both new and true to life, and second because, as a knock-on effect, it points the way to other changes.

In the next post we’ll describe one such change. Because body size considerations now create a food chain, we want to make it easier for players to see other species’ body size at a glance across the table. And THAT has lead to a new way to represent species on the table. Stay tuned…

From the sea,

Brian and Nick

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