Gridworld is an artificial life and evolution simulator. It simulates a 2D, grid-based ecosystem where virtual creatures struggle to survive, adapt, and evolve through natural selection. Watch them learn to find food, avoid danger, and compete to survive. Let them thrive on their own, or step in with world editing tools and scenarios to shape their fate.

Creatures

Creatures appear as colored tiles with tiny subcells that represent neurons. You can see them move around, eating food to stay alive and eventually reproduce if they are successful enough. Each has a body and a neural network brain encoded in DNA.

• Input neurons sense the environment.

• Signals pass through the neural network.

• Output neurons trigger behaviors such as moving, rotating, reproducing, eating, or attacking.

The Primordial Soup

You begin with a world full of food and randomly generated creatures. Most cannot feed or reproduce, and their genes die with them.

Eventually, one random DNA combination succeeds, resulting in a creature that can eat and reproduce. It multiplies rapidly, sparking a population explosion and the start of evolution.

Genesis

Don’t have the patience to wait?

No problem, several scenarios with simple premade creatures are available.

These let evolution start immediately so you can focus on watching adaptation and natural selection unfold rather than waiting for the first self-replicating creature to appear.

Evolution in Action

When creatures reproduce, DNA may mutate.

• Some mutations are beneficial, improving survival.

• Others are harmful or neutral.

• Successful mutations spread, unsuccessful ones die out.

This ongoing cycle of mutation and selection drives adaptation.

Because creatures live fast, you can observe evolution over hours or days, instead of thousands of years.

Your Role

Evolution happens automatically, you don’t need to guide it.

Start a simulation, let it run, and check back later to see what has emerged.

Want more control?

• Use the world editor to create new challenges.

• Adjust simulation settings to change environmental conditions.

• Intervene during simulations to see how populations react and force them to overcome new challenges.

What You Might Observe

Over time, many natural phenomena can emerge:

Behavior and Adaptation

• Development of food-finding skills

• Emergence of danger-avoidance behaviors

• Predatory ambush tactics

• Coevolutionary arms races

• Temporary multicellular clusters, where creatures combine into larger forms to hunt prey

Population Dynamics

• Population booms and busts

• Predator–prey population splits

• Speciation, as populations split into distinct species adapted to different niches

• Viruses and parasites replicating by exploiting other creatures

• Viral outbreaks that can wipe out large parts of the population

Every simulation is unique.

Start your own world, watch evolution unfold, and discover what forms of life will emerge in Gridworld.