Externality

About this model

This diagram models the economic dynamics and player interactions surrounding a world boss fight in an MMO (Massively Multiplayer Online) game. It examines how the number of players attacking a boss affects both the likelihood of defeating the boss and the distribution of loot among players, illustrating both positive and negative externalities. Positive externalities are represented by the increased chance of success as more players join the fight, calculated through a formula that exponentially increases the win rate with the number of players, capped at 100%. Negative externalities manifest when the loot per player decreases as more players participate, distributed according to a formula that divides total loot by the number of players involved.

The diagram further quantifies these interactions through registers that calculate the average loot per player, highlighting the tipping point where the addition of more players leads to diminishing returns for each individual. This system underscores the strategic considerations players must weigh when joining a boss fight, balancing the benefits of an increased success rate against the potential reduction in individual rewards. This exploration of externalities in an MMO context reveals the complex interplay between player actions and game outcomes, providing a sandbox for understanding economic principles in a virtual setting.

“Externality” is a public Machinations diagram by Harry Ashton, shared in the Machinations Community.

You can open the original diagram in the Machinations app, press Play to watch how resources move through it, and change its values to see how the system responds. Machinations is a visual tool for designing, simulating and balancing game economies and other systems, where resources flow through sources, pools, drains, converters and gates. In a diagram, a source creates resources, a pool stores them, a drain removes them, a converter changes one resource into another and a gate decides where they go next.