Mewgenics Beginner’s Guide

Mewgenics is a roguelite tactics game developed by Edmund McMillen and Tyler Glaiel in which you breed, raise, and battle cats. The premise sounds whimsical; the depth is not. Under the surface is a genetics simulator, a turn-based combat system, and a run structure that asks you to make consequential decisions with limited information from the very first screen. This guide covers what you actually need to know before your first run.

The Core Loop

Mewgenics alternates between two phases:

1. Breeding phase — You manage your cats, pair them to produce offspring, and decide which kittens to keep, develop, or discard. Genetic decisions here determine the quality ceiling of your team for the rest of the run.

2. Combat phase — Your cats fight on a 10×10 grid against enemy encounters. Combat is turn-based and positional; the size of the grid means range, movement, and positioning all matter. Cats with higher SPD act earlier; cats with better combat stats and spells deal more damage or survive longer.

These two phases feed each other. Better genetics produce better fighters; surviving combat gives you resources and progression to develop your breeding program further.

The Seven Stats

Every cat has seven core stats. Understanding what each does helps you evaluate trait bonuses and collar choices:

Most of your genetic work will focus on two or three stats that match your chosen collar class. You don’t need to raise all seven equally — specialization wins more consistently than generalism, especially in early runs.

Starter Collars

Your first cat’s collar is the most important decision in run setup. It defines the class role and the stat focus of your starting bloodline. The five starters:

• Collarless — No specialization. Flexible for breeding but weak in combat without deliberate development. Not recommended for first runs.
• Fighter — Melee class, primary stat STR. Direct and reliable. The best choice for learning the game because relevant traits are often dominant and show results quickly.
• Hunter — Ranged class, primary stat DEX. Safer positioning in combat; higher genetic investment to peak.
• Mage — Spell class, primary stat INT. Highest ceiling; hardest to execute. Requires understanding spell inheritance before the class pays off.
• Tank — Durability class, primary stat CON. Absorbs damage for your team; most impactful in two-cat compositions.

If this is your first run, start with Fighter. You’ll see the effect of your breeding choices faster, and the combat feedback loop is more legible.

Genetics: What You Need to Know First

Every trait in Mewgenics is controlled by dominant or recessive alleles. The short version:

• Dominant traits express when a cat has at least one copy. You don’t need to breed two of them together to see the trait appear.
• Recessive traits only express when a cat has two copies — one from each parent. A cat can carry a recessive allele silently, passing it to offspring without ever showing it.

This matters immediately because the game will show you cats that seem similar on the surface but differ in what alleles they carry. A cat carrying a hidden recessive trait for +3 LCK is genetically more valuable than it looks — but only if you breed it with another carrier.

Three concrete examples from the game:

• Strong (+3 STR) is dominant — one copy is enough.
• Weak (−2 STR) is recessive — doesn’t hurt your cat unless it has two copies.
• Lucky (+3 LCK) is recessive — needs two copies to express, but worth pursuing.

Early advice: don’t discard cats just because they don’t express a trait you want. Carriers are often your most valuable breeding stock.

Spells and the Stimulation Breakpoint

Cats can hold up to 4 spells. With over 1000 abilities in the game, the spell pool is enormous, and spells are a major source of combat differentiation between cats of similar stat levels.

Spells are inherited during birth, and the room’s Stimulation level affects the outcome. When Stimulation reaches 32, births are guaranteed to produce offspring that inherit at least one spell. Below that threshold, spell inheritance is probabilistic. In practical terms: when you want to pass a specific spell to a kitten, don’t breed in a low-Stimulation room.

You won’t need to worry about optimizing Stimulation on your first run, but you should notice the mechanic and start building toward it once your team has consistent spell-carriers.

Combat on the 10×10 Grid

Combat in Mewgenics is positional. On the 10×10 grid:

• Range determines who your cat can target without moving. Hunters and spell-casting Mages benefit most from range.
• SPD determines turn order. Fast cats act earlier, which can mean the difference between landing a spell before an enemy or after.
• Positioning determines who takes melee hits. Your Tank should be in front. Your Mage or Hunter should have space to operate without being engaged in melee.

In early fights, the grid is forgiving because enemies are simple. In later encounters, enemy abilities and compositions become complex enough that positioning mistakes cascade quickly. Start learning to read the grid early, before the fights demand it.

What to Focus on in Run 1

1. Pick Fighter. Learn how breeding affects combat output before adding spell complexity.
2. Keep carriers. Any cat that seems genetically interesting — even if it doesn’t express the trait you want — is worth holding until you understand its alleles.
3. Notice Stimulation. You don’t need to optimize it yet, but start recognizing when it’s high or low.
4. Don’t spread your stat focus. Pick two stats to build toward (STR and CON for Fighter, for example) and ignore the rest in early generations.
5. Lose and learn. First runs in roguelites are research. The genetic knowledge you build carries into subsequent runs even when the run itself ends.

Go Deeper

Once you have the basics, the genetics guide on dominant vs recessive traits will answer questions your first run is going to raise. The class tier list covers each collar in more depth if you’re deciding what to try next.

And when you’re ready to start planning your breeding lines rather than reacting to them, the tools on this site are built for exactly that.