# Interactive Story Draft

- **File Format:** `.isd`

The Interactive Story Draft (ISD) format is a intermediate language designed for drafting interactive fiction before implementation in Twine’s Harlowe or similar engines. It allows authors to structure branching narratives, define conditions, and track variables efficiently.

---

### Specifications

1. **Passages:**
   
   - **Syntax:** `:: PassageName`
   - **Description:** Defines a new passage or section in the story.

2. **Links:**
   
   - **Syntax:** `[[Link Text -> TargetPassage]]`
   - **Description:** Creates a navigational link to another passage.

3. **Variables:**
   
   - **Syntax:** `$variableName`
   - **Description:** Represents a variable to track states or information.

4. **Variable Assignment:**
   
   - **Syntax:** `(set: $variableName to value)`
   - **Description:** Assigns a value to a variable.

5. **Conditional Statements:**
   
   - **Syntax:** `(if: condition)[Text if true]`
   - **Description:** Displays text or content based on a condition.

6. **Else Clause:**
   
   - **Syntax:** `(else:)[Text if false]`
   - **Description:** Follows an `(if:)` statement to handle the false condition.

7. **Drop down:**
   
   - **Syntax:** ``(dropdown: $variableName to "Option 1", "Option 2")``
   - **Description:** Assigns a drop down menu with the given strings as options.

8. **Random Number Generation:**
   
   - **Syntax:** `(set: $variableName to (random: min, max))`
   - **Description:** Sets a variable to a random number between `min` and `max`.

9. **Text Styling:**
   
   - **Syntax:** `''italic''`, `'''bold'''`, `^^superscript^^`, `~~subscript~~`
   - **Description:** Applies basic text formatting.

### Usage

```
:: Introduction
Welcome to your adventure! You find yourself at a crossroads.

[[Take the left path -> LeftPath]]
[[Take the right path -> RightPath]]

:: LeftPath
You walk down the left path and encounter a mysterious stranger.

(set: $hasKey to true)
The stranger gives you a key.

[[Continue -> Crossroads]]

:: RightPath
You walk down the right path and find a locked door.

(if: $hasKey)[
    You use the key to unlock the door and discover a treasure!
]
(else:)[
    The door is locked. You need a key to open it.
]

[[Return to the crossroads -> Crossroads]]

:: Crossroads
You're back at the crossroads.

[[Take the left path -> LeftPath]]
[[Take the right path -> RightPath]]
```