• Each game has 10 frames
• Each frame has 2 turns to score 10 pins
• Each frame has bonuses for strikes and spares
• A spare is when all 10 pins are knocked down in 2 turns
• A strike is when all pins are knocked down in 1 turn
• The bonus for spares is equal to current frame (10 pins) plus the number of pins on the next roll.
• The bonus for strikes is equal to the current frame plus the next 2 rolls.
• In the 10th frame, if the player rolls a strike or spare, they get an extra roll for a maximum of 3.

Use TDD to implement the game rules. Keep it as simple as possible.