Explanation:

- Let's break down the options:

- Punishable: A contract’s illegality might lead to criminal consequences, but not every illegal contract is punishable by law. It's not the main effect on contract validity.

- Void: An illegal contract is automatically void. It cannot be enforced by law from the beginning itself. This is the key legal effect of illegality in contracts.

- IIIegal: This is just repeating the idea of illegality, not stating its effect.

- All of these: Not all are correct, as the main legal consequence is "void."

Correct Answer: Option 2 – Void