Final answer:
Under the Restatement of Contracts, Section 16, Charles might have the ability to avoid the contract involving Tessa due to intoxication if he can prove that his intoxication rendered him incapable of understanding the consequences of his actions and the nature of the contract.
Step-by-step explanation:
The Restatement of Contracts, Section 16, provides a basis for avoiding a contract if one party was intoxicated to the extent that they couldn't comprehend the terms or the implications of their agreement. Charles might have grounds to disavow the contract related to defaming Tessa if he can demonstrate that his intoxication was severe enough to impair his judgment significantly. However, simply being intoxicated might not automatically invalidate the contract; Charles needs to prove that his level of intoxication affected his ability to comprehend the contract's terms and implications. This could involve showing that he lacked understanding or that Bobby took advantage of his intoxicated state. If Charles can substantiate this, he might successfully avoid the contract involving Tessa due to his intoxication.
Summary: Charles might be able to avoid the contract involving Tessa if he can prove his intoxication rendered him incapable of understanding the contract's nature and consequences.