The main objective of Scary Teacher 3D is to take revenge on your scary teacher by completing various missions. Players must sneak around, avoid being caught, and perform pranks on the teacher to progress through the game.

To complete missions, find the objective, interact with objects, and execute the prank carefully. Each mission requires a combination of stealth and strategy to ensure the teacher doesn’t notice your actions.

Yes, you can freely explore the teacher's house and school. This open-world aspect allows you to discover hidden items, various rooms, and plan your pranks effectively.

If you get caught, you'll have to restart the mission. To avoid this, use stealth, listen for the teacher's sounds, and plan your moves carefully. Awareness of her patrols can help you succeed.

Effectively planning pranks involves several steps:
1. Familiarize yourself with the teacher’s routine to know when she’s out of sight.
2. Identify potential objects around the house that can aid in executing your prank.
3. Choose the right time and location to ensure you are not caught.
4. Execute the plan quickly and escape before being detected.