The Tower Experiment: blending F2P gaming and tokens in Crazy Defense Heroes and Crazy Kings

Animoca Brands
Tower Ecosystem
Published in
6 min readFeb 15, 2021

A crypto experiment on the future of F2P gaming

At Animoca Brands we fully and unreservedly embrace blockchain and play-to-earn as the future of gaming, but a major part of our income still derives from free-to-play (F2P) games, such as Power Rangers: Legacy Wars, Crazy Defense Heroes, and Snoopy’s Town Tale. As a result, we spend a lot of time considering the question of how to combine blockchain economics with F2P inflationary game design. We have come up with an experimental method to blend together elements of these two very different systems.

F2P and play-to-earn: different by design

Combining blockchain and F2P gaming is challenging for a couple of reasons.

The first is the obvious one, which is that blockchain games usually require fairly significant payment that is antithetical to F2P.

The second is that F2P games are inflationary by design: increases in player base and activity lead to decreases in the scarcity and value of in-game assets. When a player obtains a reward in a standard F2P game, the value he or she receives is created ex nihilo. For example: you kill ten rats and are rewarded with gold and a level 1 potion that the game generates out of nothing, as needed. Every time someone completes the objective to kill 10 rats, more gold and more potions are automatically added to the game economy — effectively without limit. The value of gold and level 1 potions will therefore decrease over time as these virtual assets become more abundant (less scarce); this is inflation at work.

The inflationary model of F2P gaming is intentional because the generation of assets based on player activity rewards and encourages player engagement, provides a level playing field in which all participants have a fair chance, creates opportunities for monetization, and so on.

Blockchain games, on the other hand, are able to limit this inflation because the supply of game assets can be predefined and controlled. For example, our game F1® Delta Time uses the REVV ERC-20 fungible token as currency, which has a limited supply and a disclosed schedule specifying how many tokens can be issued over time.

What all this means is that F2P gaming and blockchain gaming approach virtual economies in fundamentally different ways: F2P games are designed to be inflationary in order to generate revenue at the expense of a game’s virtual assets and their scarcity; whereas blockchain games typically seek to generate value for their virtual assets and their scarcity.

Reconciling the twain

One of our goals at Animoca Brands is to bring regular gamers into blockchain games. Until now, the way we have done this is to redesign an existing F2P game and its economy for blockchain.

The best example of this is the Sandbox mobile game franchise for Android and iOS, a series of world and game-creation F2P games with millions of users. We are developing The Sandbox into a new, bigger and bolder multiplayer blockchain title that boasts a virtual economy based entirely on fungible and non-fungible tokens. Our goal for this new game is to create a player-driven multiverse of experiences and expression for all sorts of people: creators, gamers, artists, collectors, businesspeople, and more. You can check it out at as well as the SAND token.

The Sandbox for blockchain is, effectively, a new game that was designed almost completely from scratch. Although it is based on its mobile game predecessors in the franchise, its design and development have required years of effort and considerable investment.

What if we could allow existing F2P games to take advantage of blockchain, serve as an introduction to the world of crypto, and offer players the benefits of decentralized economies? Enter the Tower Experiment.

Saga of the Legend of the Tower Experiment

In the closing decade of the 16th century, the great Italian scientist Galileo Galilei is said to have dropped two different objects simultaneously from the Leaning Tower of Pisa to demonstrate that the rate at which objects fall is independent of their mass. This has become known as the Leaning Tower of Pisa Experiment, sometimes informally shortened to the Tower Experiment.

We’re not talking about that kind of tower or that kind of experiment, but anyone interested in the matter should check out commander David R. Scott performing the experiment on the Moon about 380 years after Galileo’s observation.

Our tower experiment involves the creation of a system that attempts to maintain balance and equitability in a F2P game while introducing the value of blockchain features, including NFTs, DeFi, and governance. To do this, we are going to use one of our most successful franchises: the Crazy Kings games.

The token and a new game: tower defense reimagined

Crazy Kings (CK) and its sequel Crazy Defense Heroes (CDH) are among our most venerable and respected mobile games. They are successful tower defense games boasting millions of downloads, solid financial results and a number of blockchain-friendly features, including the deck building of a collectible card game and an RPG character/equipment system.

We are going to introduce a new fungible crypto token for CK and CDH that will have various utility for the entire Crazy Kings franchise and will pave the way for a new blockchain game. Some highlights of our Tower Experiment:

Governance: owners of the tokens will be able to fully participate in the governance of the Crazy Kings franchise, including submitting proposals for the games’ direction and voting on those proposals; these are important steps in giving players a true and effective voice in the roadmap of the game

Crypto economy: owners of the tokens will be able to trade them, thus buying and selling the right to influence the development of the game franchise, and even participate in distributed finance (DeFi) initiatives such as staking (details to be determined)

NFTs: assets in Crazy Kings and Crazy Defense Heroes are represented by game cards, which have different power, value, and rarity. Players will use the token to purchase collectible NFTs that correspond to in-game items; the NFTs will have certain functionalities in the existing games and in the new game

NFT minting: owners of the token will be able to mint NFTs that correspond to in-game cards. Players will be able to trade the NFTs

Currency: the token will be accepted as currency within a PC based blockchain native game that will be the newest addition to the Crazy Kings franchise

Tournament entry fees: tournaments are special events that will challenge the skill, strategy, and game assets of players

Tournament prizes: tokens will be distributed as prizes to the victors of competitive multiplayer tournaments, which is a significant step toward full-fledged play-to-earn mechanics.

Earn the token by playing CK and CDH

If the project sketched above is successful, we may be looking at a viable path for traditional games to embrace blockchain — time will tell. In the short term, we will launch an initiative for players of Crazy Kings and Crazy Defense Heroes to “farm” the new tokens simply by playing those games — and have fun playing them!

More details will be forthcoming soon. For now, if you are not already playing Crazy Kings or Crazy Defense Heroes — what are you waiting for? Familiarize yourself with these sophisticated and polished tower defense games at Crazy Kings (iOS) and Crazy Defense Heroes (Android and iOS).

Please note that we are not doing a token sale at this time; the only way to obtain the new token is by playing Crazy Kings or Crazy Defense Heroes. So get ready to start farming the new tokens and sign up at to receive updates on this project.

Originally published at on February 15, 2021.