Card Effects

Card effects are the mechanisms through which cards interact with the game state. This section documents how card effects are implemented, resolved, and tested in Rummage.

Overview

Magic: The Gathering cards have a wide variety of effects that modify the game state in different ways:

Adding or removing counters
Dealing damage
Moving cards between zones
Modifying attributes of other cards
Creating tokens
Altering the rules of the game

The effect system in Rummage is designed to handle all these interactions in a consistent and extensible way.

Implementation Approach

Effects are implemented using a combination of:

Components: Data that defines the effect's properties
Systems: Logic that processes and applies the effects
Events: Notifications that trigger and respond to effects
Queries: Selections of target entities to affect

Core Components

Effect Resolution: How effects are processed and applied
Targeting: How targets are selected and validated
Complex Interactions: Handling interactions between multiple effects
Special Card Implementations: Cards with unique game-altering effects like subgames and game restarting

Integration

The effects system integrates with:

State Management: Effects modify game state
Event System: Effects are triggered by and generate events
MTG Rules: Effects follow the comprehensive rules
Subgames and Game Restarting: Special rules for cards like Shahrazad and Karn Liberated

Testing