diff --git a/backend/app/models/championship.py b/backend/app/models/championship.py
index c61d7ad..13bc139 100644
--- a/backend/app/models/championship.py
+++ b/backend/app/models/championship.py
@@ -1,7 +1,7 @@
 import uuid
 from datetime import datetime
 
-from sqlalchemy import DateTime, Float, Integer, String, Text, Uuid, func
+from sqlalchemy import DateTime, Float, ForeignKey, Integer, String, Text, Uuid, func
 from sqlalchemy.orm import Mapped, mapped_column, relationship
 
 from app.database import Base
@@ -11,19 +11,21 @@ class Championship(Base):
     __tablename__ = "championships"
 
     id: Mapped[uuid.UUID] = mapped_column(Uuid(as_uuid=True), primary_key=True, default=uuid.uuid4)
+    org_id: Mapped[uuid.UUID | None] = mapped_column(Uuid(as_uuid=True), ForeignKey("organizations.id", ondelete="SET NULL"))
     title: Mapped[str] = mapped_column(String(255), nullable=False)
+    subtitle: Mapped[str | None] = mapped_column(String(255))
     description: Mapped[str | None] = mapped_column(Text)
     location: Mapped[str | None] = mapped_column(String(500))
+    venue: Mapped[str | None] = mapped_column(String(255))
     event_date: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
     registration_open_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
     registration_close_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
+    accent_color: Mapped[str | None] = mapped_column(String(20))  # hex color e.g. #FF5CA8
 
-    # Extended fields
+    # Legacy flat fields (kept for backwards compat, replaced by relational tables in POL-7 to POL-11)
     form_url: Mapped[str | None] = mapped_column(String(2048))
     entry_fee: Mapped[float | None] = mapped_column(Float)
     video_max_duration: Mapped[int | None] = mapped_column(Integer)  # seconds
-    judges: Mapped[str | None] = mapped_column(Text)       # JSON string: [{name, bio, instagram}]
-    categories: Mapped[str | None] = mapped_column(Text)  # JSON string: [str]
 
     # Status: 'draft' | 'open' | 'closed' | 'completed'
     status: Mapped[str] = mapped_column(String(20), nullable=False, default="draft")
@@ -38,5 +40,11 @@ class Championship(Base):
         DateTime(timezone=True), server_default=func.now(), onupdate=func.now()
     )
 
+    organization: Mapped["Organization | None"] = relationship(back_populates="championships")  # type: ignore[name-defined]
     registrations: Mapped[list["Registration"]] = relationship(back_populates="championship", cascade="all, delete-orphan")  # type: ignore[name-defined]
     participant_list: Mapped["ParticipantList | None"] = relationship(back_populates="championship", uselist=False, cascade="all, delete-orphan")  # type: ignore[name-defined]
+    disciplines: Mapped[list["Discipline"]] = relationship(back_populates="championship", cascade="all, delete-orphan")  # type: ignore[name-defined]
+    styles: Mapped[list["Style"]] = relationship(back_populates="championship", cascade="all, delete-orphan")  # type: ignore[name-defined]
+    fees: Mapped["Fee | None"] = relationship(back_populates="championship", uselist=False, cascade="all, delete-orphan")  # type: ignore[name-defined]
+    rules: Mapped[list["Rule"]] = relationship(back_populates="championship", cascade="all, delete-orphan")  # type: ignore[name-defined]
+    judges_list: Mapped[list["Judge"]] = relationship(back_populates="championship", cascade="all, delete-orphan")  # type: ignore[name-defined]