Cat and Mouse Games: A Genre (Game Design)

There was a period of time where Cat and Mouse (CnM) games were a prolific genre on various Real Time Strategy Games (RTS) (2010-2014, in my estimation). They were a prominent subset of games developed by individuals (generally) unaffiliated with Blizzard, who made use of the accompanying scenario editor to develop their own custom games. In this article I aim to explain what a Cat and Mouse game is, and why they’re interesting to study as a genre.

One can also view this article as a historical look into a subset of the Real Time Strategy Games custom games community in that period, and build upon this article in that reading as well.

What is a Cat and Mouse Game?

Cat and mouse games are asymmetric games, with two groups of opposing players — cats, and mice. Cats chase mice down, and the mice aim to hide long enough to defeat the cats.

Cats are much stronger than the mice early on, and so, mice have to build bases and gather resources in order to challenge the cats openly later on in the game.

There’s various spins on this: Cops and Robbers, Farmers and Hunters, Titans and Minions, Vampires and Humans, Parasite… To decipher which is the cat and the mouse in these cases is left as an exercise to the reader.

This genre of game was first revealed to me in Starcraft I, and provides the namesake for this genre I dub “Cat and Mouse”.

Cat and Mouse Mechanics.

The cats typically begin with far more strength and health than the mice. The mice often die in a few hits and can build, whereas the cats may recruit minions to their side using the money they accumulate from destroying mice buildings or capturing mice.

Mice aim to gather resources, build their base up and work together with the other mice to defeat the cats. Cats aim to capture mice and jail them, and other mice could break them out. This introduced an element of tension for mice (shall I take the risk to save my allies) and an additional consideration for the cat (do I camp, or stay at the jail, or do I leave to hunt for the mice?)

Why does Cat and Mouse work as a game genre?

I believe Cat and Mouse works for these identifiable reasons. I will analyze Cat and Mouse with reference to Tynan Sylvester and Raph Koster.

The genre effectively creates tension and competition.

Huge emotional swings exist in the game. In Tynan’s terminology, there exists ‘large swings of human value’ — life or death, poverty or wealth, danger to safety, follower to leader. It’s electrifying when you’re the final mouse in the game with a strong base, the other mice are counting on you and hiding in your base… and you’re against 5 cats and their minions.

After a cat breaks into a base, the fragile underbelly of the base is revealed. The cats may then plunder that for resources (and subsequent ammunition and upgrades against the bases of the other mice.) The tension of the game rivals the large swing that can happen in a DotA 2 teamfight, or in a particularly intense chess match (watch Carlsen blunder).

Most interactions in the game are interesting to all players.

This results in high story-richness (“the percentage of interactions in a game that are interesting to a player — Tynan”). Mice are interested in what the other mice are up to, and in the position of the cats at all times, and vice versa. This could be the difference between life and death for a mouse, and a juicy catch for a cat!

Additionally, these games encourage you to discover and learn various tricks and timings. (with reference to Raph Koster) Through the course of multiple games, you formulate benchmarks for yourself to determine what’s a good “Slayer timing” in Vampirism Fire, for example.

Players are excited about progression, wealth and acquisition. 

Everyone likes seeing numbers go up. One of the fundamental drivers of human desire is: “I want more.” Feeling a sense of progression and then being able to actualize that can be tremendously rewarding. For the cats, often they can buy upgrades and helper units from “farming” mice buildings and units, and see their damage go up.

Emotion through teamwork and striving.

Teamwork and solidarity is key in such games. You’re incentivized to educate, help and shelter your fellow mice. If they fail, the cats get that much stronger and that may be just enough… to take you down.

On the other hand, Cats can help each other siege down bases. They need to work together to coordinate their healing, teleportation, spells and other tricks to get the upper hand.

Moments of sheer excitement: the hide and seek factor.

Even when captured, it’s joyful seeing when the cats go past and miss your ally’s hidden base. It’s lovely when a mouse slips through the back door to escape a cat pulverizing their base. The fun for the cats: the thrill of discovering a secret base, or discovering a mouse’s secret hiding spot and cornering them, or the joy of a slow siege finally working out!

All these factors lead to a satisfying and engaged game experience for both cats and mice. In the end, the ability to turn the tables also leads to a dynamic experience — the hunter may become the hunted. In the meantime, Mice have their own ways of striking back — such as killing the minions of the cat.

I will discuss some variations on the basic Cat and Mouse formula and how they affect the experience of the game.

Variations on Cat and Mouse

It is key to note that these games have been implemented multiple times, across multiple versions and platforms. (Look at that versioning on Island Defense — 3.0.9d!) I refer then to the general form of the game rather than any specific version.

Vampirism Fire

Vampirism Fire pits Vampires (cats) against Humans (mice). Vampires can now buy items that allow them to do a variety of things, such as teleport and summon. They may level up and cast spells that ‘nuke’ the humans while they repair their walls.

There are a variety of strategies that Vampires may spend their money on in order to break a base (items? minions? upgrades?). There are different considerations of economy for the Humans (do I build up my defense, or do I go for a greedy economy?). It is then crucial for both teams to monitor the strength of the other at any given point in time.

Island Defense

In Island Defense, Builders (Mice) hide from Titans (Cats). It carries on innovations from Vampirism Fire (Hero units — “Titan Hunters”). Island Defense also introduces different classes of Builders and Titans with specialisations and abilities.

For instance, the Satyr doesn’t build workers to harvest like other Builders, and instead gains resources from harassing the Titan. In turn, his base building is minimal but he can be a real pain in the Titan’s side.

Titans also can vary widely. There are Titans that have high mobility, variations on their nukes, their healing abilities. This leads to varied gameplay and different aspects to learn for the players and ensures high replayability.

Parasite

This is an interesting variation, along with Evolve, and this may be moving slightly out of scope — Parasite has a lot in common with “Social Deduction” type games, which include classic games such as Mafia and Werewolf. One player is the Alien (or Parasite), and can disguise as a Human, and the rest are Humans attempting to find the Parasite. The parasite aims to infect the other humans. There is resource gathering but there is no base building, and so the tension comes more from suspense and mystery, as opposed to chasing and hiding. It’s worth discussing the genres’ overlaps and divergences in a further article.

Challenges In Developing Cat and Mouse Games

I believe there is still plenty of space to explore the development of Cat and Mouse games, and I wonder why they aren’t popular yet on free-to-play mobile, for example, given the appealing factors stated above.

Here are some of my personal hypotheses for the inherent difficulty in developing and designing Cat and Mouse games.

It is difficult to balance asymmetric games.

In a competitive setting, and in asymmetric games, balance is important to ensure a healthy player experience. Cat and Mouse games suffer particularly from this as much of the game relies on the cats and mice being relatively even in skill. If there is even one mouse that “feeds” a cat, they may snowball quickly out of control, which leads to an unfun experience for the mice.

If you were to introduce multiple classes, you’d have to balance them all. The amount of complexity and effort required to balance scales exponentially with each new class of mouse and cat you introduce. Matchmaking could be a significant challenge as well given the asymmetric nature of the game — you could consider having a “Cat” MMR and a “Mouse” MMR.

The game is especially unfun when the teams are not well matched.

It can be frustrating to lose because your allies were too new and unable to play effectively when you’ve played to the top of your game. It can be unfun when the cats are not adequately skilled and leave the game, or worse, quit.

DotA 2 and CounterStrike mitigate this somewhat with their low-priority matchmaking system, which de-prioritizes players from joining a game if they have ‘abandoned’ a game previously, and its report system, which allows players to report others for ‘bad behaviour’.

If we plan to implement a mobile version of Cat and Mouse, however, we must compare it to competitors of similar duration such as Mobile Legends and PUBG Mobile.

Mobile Legends has a similar abandon mechanic and frowns upon players leaving games early. PUBG Mobile however, is not as harsh but prevents you progressing in ‘level’ if you don’t finish games. With levels, a tiered approach towards unlocking new cats and mice could be adopted, incentivizing cats and mice to stay in the game.

There isn’t an established framework for developing these games.

These games leverage heavily on the building blocks of the Warcraft III, Starcraft and Starcraft II map editors. The editors abstract work such as handling resource gathering, pathfinding, map building, assets and sound, which allow a quick iterative cycle for devs. Additionally, they tap upon an existing player base (those who own RTS games and enjoy custom games).

There is a lot of work required in building up these systems, and there is no guarantee that a more general audience would enjoy these games compared to other ‘proven’ game genres (Battle Royales, Auto Battlers, and MoBAs, to name a few).

Cat and Mouse Today

Communities

Up till today, (2020), players still record their gameplay and post it on YouTube. Rugarus, the current developer of Vampirism Fire, still shares his gameplay videos, where he educates others on how to play effectively. Yes, there is a certain joy both in education and in growing that makes games enjoyable. (Koster)

In 2014, Evolve was developed. This marked an innovation in the Cat and Mouse genre, pitting 4 hunters against 1 monster. In Evolve, the cats are the hunters, and the monster is the mouse — the monster has to gather resources by chewing up wildlife and evolving, and the hunter aims to subdue the monster before that. Once the monster has evolved to its final stage, it will be strong enough to take on the hunters and pick them off.

An aside: I believe A Cat and Mouse game that aims to leverage on the mechanics of economy and building will be competing with titles such as Mobile Legends and PUBG Mobile rather than games such as Brawl Stars, due to concerns of duration. However, one must remain open to see if the genre stands up as ‘fun’ even without the economic aspects.

Further articles may explore possible monetization strategies for such cat and mouse games. “Will skins be enough to monetize and pay for development successfully? Would access to special cats / mice lead to accusations of ‘pay to win’?”

Other fruitful paths may be to compare and contrast genres, deep dive and analyze one of the variations of Cat and Mouse games, or consider how a mobile adaptation for Cat and Mouse might look like.

In summation, I’d love to see a Cat and Mouse game appear outside of the traditional RTS custom games circuit.

I’d also love to work on an adaptation for mobile that can be just as engaging. We don’t know what a mobile version of CnM might look like, but I think it’s worth trying.

Please e-mail me at [email protected] if you’ve enjoyed reading this article, have any feedback or just wish to connect! 🙂