  We study the competition between blockchains in a \emph{multi-chain}
environment, where a dominant EVM-compatible blockchain (e.g., Ethereum)
co-exists with an alternative EVM-compatible (e.g., Avalanche) and an
EVM-incompatible (e.g., Algorand) blockchain. While EVM compatibility allows
existing Ethereum users and developers to migrate more easily over to the
alternative layer-1, EVM incompatibility might allow the firms to build more
loyal and ``sticky'' user base, and in turn a more robust ecosystem. As such,
the choice to be EVM-compatible is not merely a technological decision, but
also an important strategic decision. In this paper, we develop a game
theoretic model to study this competitive dynamic, and find that at
equilibrium, new entrants/developers tend to adopt the dominant blockchain. To
avoid adoption failure, the alternative blockchains have to either (1) directly
subsidize the new entrant firms or (2) offer better features, which in practice
can take form in lower transaction costs, faster finality, or larger network
effects. We find that it is easier for EVM-compatible blockchains to attract
users through direct subsidy, while it is more efficient for EVM-incompatible
blockchains to attract users through offering better features/products.
