# Special Gem Rules

## Overview
Special gems are unique game pieces that introduce new mechanics and strategic depth to Gem Swap. They appear starting from **Level 2**.

## Gem Types
There are three types of special gems:
1.  **Feather**
2.  **Star**
3.  **Kitty** (Cat Head)

## Characteristics

### 1. Appearance & Spawning
*   **Introduction**: Special gems start appearing in **Level 2**.
*   **Spawning**: They do **not** appear on the initial board generation. They only appear during board refills (reloads) after matches are cleared.
*   **Colors**: A special gem can spawn in any of the 7 standard gem colors.
*   **Limit**: Only **one** special gem is allowed on the board at any given time.

### 2. Matching Rules
*   **Compatibility**: Special gems can be matched with **any** of the 7 color gems.
    *   *Implementation Note*: They act as "Wildcards". For example, a Special Gem between two Red Rubies will complete the match.
*   **Standard Matches**: They function like normal gems in matches (horizontal or vertical lines of 3+).

### 3. Special Ability: Bottom Row Auto-Clear
*   **Trigger**: When a special gem falls to the **bottom row** of the grid.
*   **Effect**:
    1.  The special gem automatically "self-matches" (activates).
    2.  It disappears from the board.
    3.  The column above it shifts down to fill the void.
    4.  A new gem falls in from the top to refill the column.
