diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0cbab99..d95e7d6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,3 +5,13 @@ All schema changes will be documented in this file.
 ## 31-10-25
 
 - Hello, World!
+- Initial PCD 2.0 schema definition
+  - Core entity tables: quality_profiles, custom_formats, regular_expressions,
+    languages, tags, qualities, quality_groups
+  - Custom format conditions system with 11 condition types (patterns, language,
+    indexer_flag, source, resolution, quality_modifier, size, release_type,
+    year)
+  - Quality profile system supporting individual qualities and quality groups
+  - Junction tables for tags, quality groups, profile qualities, and profile
+    custom formats
+  - Unique index ensuring single upgrade_until per profile
diff --git a/base/1.initial.sql b/base/1.initial.sql
new file mode 100644
index 0000000..d82325d
--- /dev/null
+++ b/base/1.initial.sql
@@ -0,0 +1,243 @@
+-- ============================================================================
+-- PCD SCHEMA v1
+-- ============================================================================
+
+-- ============================================================================
+-- CORE ENTITY TABLES (Independent - No Foreign Key Dependencies)
+-- ============================================================================
+-- These tables form the foundation and can be populated in any order
+
+-- Tags are reusable labels that can be applied to multiple entity types
+CREATE TABLE tags (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    name VARCHAR(50) UNIQUE NOT NULL,
+    created_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP
+);
+
+-- Languages used for profile configuration and custom format conditions
+CREATE TABLE languages (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    name VARCHAR(30) UNIQUE NOT NULL,
+    created_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    updated_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP
+);
+
+-- Regular expressions used in custom format pattern conditions
+CREATE TABLE regular_expressions (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    name VARCHAR(100) UNIQUE NOT NULL,
+    pattern TEXT NOT NULL,
+    regex101_id VARCHAR(50),  -- Optional link to regex101.com for testing
+    description TEXT,
+    created_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    updated_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP
+);
+
+-- Individual quality definitions (e.g., "1080p Bluray", "2160p REMUX")
+CREATE TABLE qualities (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    name VARCHAR(100) UNIQUE NOT NULL,
+    created_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    updated_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP
+);
+
+-- Quality groups combine multiple qualities treated as equivalent
+CREATE TABLE quality_groups (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    name VARCHAR(100) UNIQUE NOT NULL,
+    created_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    updated_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP
+);
+
+-- Custom formats define patterns and conditions for media matching
+CREATE TABLE custom_formats (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    name VARCHAR(100) UNIQUE NOT NULL,
+    description TEXT,
+    created_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    updated_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP
+);
+
+-- ============================================================================
+-- DEPENDENT ENTITY TABLES (Depend on Core Entities)
+-- ============================================================================
+
+-- Quality profiles define complete media acquisition strategies
+CREATE TABLE quality_profiles (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    name VARCHAR(100) UNIQUE NOT NULL,
+    description TEXT,
+    upgrades_allowed INTEGER NOT NULL DEFAULT 1,
+    minimum_custom_format_score INTEGER NOT NULL DEFAULT 0,
+    upgrade_until_score INTEGER NOT NULL DEFAULT 0,
+    upgrade_score_increment INTEGER NOT NULL DEFAULT 1 CHECK (upgrade_score_increment > 0),
+    language_id INTEGER NOT NULL,
+    created_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    updated_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    FOREIGN KEY (language_id) REFERENCES languages(id)
+);
+
+-- Conditions define the matching logic for custom formats
+-- Each condition has a type and corresponding data in a type-specific table
+CREATE TABLE custom_format_conditions (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    custom_format_id INTEGER NOT NULL,
+    name VARCHAR(100) NOT NULL,
+    type VARCHAR(50) NOT NULL,  -- release_title, release_group, edition, language, etc.
+    negate INTEGER NOT NULL DEFAULT 0,  -- Invert the match (e.g., "NOT language")
+    required INTEGER NOT NULL DEFAULT 0,  -- Condition must match for format to apply
+    created_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    updated_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    FOREIGN KEY (custom_format_id) REFERENCES custom_formats(id) ON DELETE CASCADE
+);
+
+-- ============================================================================
+-- JUNCTION TABLES (Many-to-Many Relationships)
+-- ============================================================================
+
+-- Link regular expressions to tags
+CREATE TABLE regular_expression_tags (
+    regular_expression_id INTEGER NOT NULL,
+    tag_id INTEGER NOT NULL,
+    PRIMARY KEY (regular_expression_id, tag_id),
+    FOREIGN KEY (regular_expression_id) REFERENCES regular_expressions(id) ON DELETE CASCADE,
+    FOREIGN KEY (tag_id) REFERENCES tags(id) ON DELETE CASCADE
+);
+
+-- Link custom formats to tags
+CREATE TABLE custom_format_tags (
+    custom_format_id INTEGER NOT NULL,
+    tag_id INTEGER NOT NULL,
+    PRIMARY KEY (custom_format_id, tag_id),
+    FOREIGN KEY (custom_format_id) REFERENCES custom_formats(id) ON DELETE CASCADE,
+    FOREIGN KEY (tag_id) REFERENCES tags(id) ON DELETE CASCADE
+);
+
+-- Link quality profiles to tags
+CREATE TABLE quality_profile_tags (
+    quality_profile_id INTEGER NOT NULL,
+    tag_id INTEGER NOT NULL,
+    PRIMARY KEY (quality_profile_id, tag_id),
+    FOREIGN KEY (quality_profile_id) REFERENCES quality_profiles(id) ON DELETE CASCADE,
+    FOREIGN KEY (tag_id) REFERENCES tags(id) ON DELETE CASCADE
+);
+
+-- Define which qualities belong to which quality groups
+-- All qualities in a group are treated as equivalent
+CREATE TABLE quality_group_members (
+    quality_group_id INTEGER NOT NULL,
+    quality_id INTEGER NOT NULL,
+    PRIMARY KEY (quality_group_id, quality_id),
+    FOREIGN KEY (quality_group_id) REFERENCES quality_groups(id) ON DELETE CASCADE,
+    FOREIGN KEY (quality_id) REFERENCES qualities(id) ON DELETE CASCADE
+);
+
+-- Define the quality list for a profile (ordered by position)
+-- Each item references either a single quality OR a quality group (never both)
+CREATE TABLE quality_profile_qualities (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    quality_profile_id INTEGER NOT NULL,
+    quality_id INTEGER,  -- References a single quality
+    quality_group_id INTEGER,  -- OR references a quality group
+    position INTEGER NOT NULL,  -- Display order in the profile
+    upgrade_until INTEGER NOT NULL DEFAULT 0,  -- Stop upgrading at this quality
+    CHECK ((quality_id IS NOT NULL AND quality_group_id IS NULL) OR (quality_id IS NULL AND quality_group_id IS NOT NULL)),
+    FOREIGN KEY (quality_profile_id) REFERENCES quality_profiles(id) ON DELETE CASCADE,
+    FOREIGN KEY (quality_id) REFERENCES qualities(id) ON DELETE CASCADE,
+    FOREIGN KEY (quality_group_id) REFERENCES quality_groups(id) ON DELETE CASCADE
+);
+
+-- Assign custom formats to quality profiles with scoring
+-- Scores determine upgrade priority and filtering behavior
+CREATE TABLE quality_profile_custom_formats (
+    quality_profile_id INTEGER NOT NULL,
+    custom_format_id INTEGER NOT NULL,
+    score INTEGER NOT NULL,  -- Positive scores prefer, negative scores reject
+    PRIMARY KEY (quality_profile_id, custom_format_id),
+    FOREIGN KEY (quality_profile_id) REFERENCES quality_profiles(id) ON DELETE CASCADE,
+    FOREIGN KEY (custom_format_id) REFERENCES custom_formats(id) ON DELETE CASCADE
+);
+
+-- ============================================================================
+-- CUSTOM FORMAT CONDITION TYPE TABLES
+-- ============================================================================
+-- Each condition type has a dedicated table storing type-specific data
+-- A condition_id should only appear in ONE of these tables, matching its type
+
+-- Pattern-based conditions (release_title, release_group, edition)
+-- Each pattern condition references exactly one regular expression
+CREATE TABLE condition_patterns (
+    custom_format_condition_id INTEGER PRIMARY KEY,
+    regular_expression_id INTEGER NOT NULL,
+    FOREIGN KEY (custom_format_condition_id) REFERENCES custom_format_conditions(id) ON DELETE CASCADE,
+    FOREIGN KEY (regular_expression_id) REFERENCES regular_expressions(id) ON DELETE CASCADE
+);
+
+-- Language-based conditions
+CREATE TABLE condition_languages (
+    custom_format_condition_id INTEGER PRIMARY KEY,
+    language_id INTEGER NOT NULL,
+    except_language INTEGER NOT NULL DEFAULT 0,  -- Match everything EXCEPT this language
+    FOREIGN KEY (custom_format_condition_id) REFERENCES custom_format_conditions(id) ON DELETE CASCADE,
+    FOREIGN KEY (language_id) REFERENCES languages(id) ON DELETE CASCADE
+);
+
+-- Indexer flag conditions (e.g., "Scene", "Freeleech")
+CREATE TABLE condition_indexer_flags (
+    custom_format_condition_id INTEGER PRIMARY KEY,
+    flag VARCHAR(100) NOT NULL,
+    FOREIGN KEY (custom_format_condition_id) REFERENCES custom_format_conditions(id) ON DELETE CASCADE
+);
+
+-- Source conditions (e.g., "Bluray", "Web", "DVD")
+CREATE TABLE condition_sources (
+    custom_format_condition_id INTEGER PRIMARY KEY,
+    source VARCHAR(100) NOT NULL,
+    FOREIGN KEY (custom_format_condition_id) REFERENCES custom_format_conditions(id) ON DELETE CASCADE
+);
+
+-- Resolution conditions (e.g., "1080p", "2160p")
+CREATE TABLE condition_resolutions (
+    custom_format_condition_id INTEGER PRIMARY KEY,
+    resolution VARCHAR(100) NOT NULL,
+    FOREIGN KEY (custom_format_condition_id) REFERENCES custom_format_conditions(id) ON DELETE CASCADE
+);
+
+-- Quality modifier conditions (e.g., "REMUX", "WEBDL")
+CREATE TABLE condition_quality_modifiers (
+    custom_format_condition_id INTEGER PRIMARY KEY,
+    quality_modifier VARCHAR(100) NOT NULL,
+    FOREIGN KEY (custom_format_condition_id) REFERENCES custom_format_conditions(id) ON DELETE CASCADE
+);
+
+-- Size-based conditions with min/max bounds in bytes
+CREATE TABLE condition_sizes (
+    custom_format_condition_id INTEGER PRIMARY KEY,
+    min_bytes INTEGER,  -- Null means no minimum
+    max_bytes INTEGER,  -- Null means no maximum
+    FOREIGN KEY (custom_format_condition_id) REFERENCES custom_format_conditions(id) ON DELETE CASCADE
+);
+
+-- Release type conditions (e.g., "Movie", "Episode")
+CREATE TABLE condition_release_types (
+    custom_format_condition_id INTEGER PRIMARY KEY,
+    release_type VARCHAR(100) NOT NULL,
+    FOREIGN KEY (custom_format_condition_id) REFERENCES custom_format_conditions(id) ON DELETE CASCADE
+);
+
+-- Year-based conditions with min/max bounds
+CREATE TABLE condition_years (
+    custom_format_condition_id INTEGER PRIMARY KEY,
+    min_year INTEGER,  -- Null means no minimum
+    max_year INTEGER,  -- Null means no maximum
+    FOREIGN KEY (custom_format_condition_id) REFERENCES custom_format_conditions(id) ON DELETE CASCADE
+);
+
+-- ============================================================================
+-- INDEXES AND CONSTRAINTS
+-- ============================================================================
+
+-- Ensure only one quality item per profile can be marked as upgrade_until
+CREATE UNIQUE INDEX idx_one_upgrade_until_per_profile 
+ON quality_profile_qualities(quality_profile_id) 
+WHERE upgrade_until = 1;
\ No newline at end of file