What type of contract implies inequality in bargaining power and restricts one party heavily?

A contract of adhesion is characterized by its structure, where one party (the drafter) has significantly more power and control over the terms than the other party. This type of contract typically presents standard terms and conditions that the weaker party must accept in full, leading to a situation where there is little to no room for negotiation. Because of this imbalance in bargaining power, the terms are often heavily restrictive for the party with less negotiating leverage.

This is different from a conditional contract, which involves specific conditions that must be met for the contract to be valid or enforceable. Likewise, an aleatory contract is based on an uncertain event, where the outcomes can vary widely depending on circumstances, and might not involve the same type of power imbalance. A unilateral contract is one where only one party makes a promise, creating obligations for the other party only if they fulfill certain conditions, but it also does not inherently imply the same level of inequality in terms of bargaining power as a contract of adhesion does.

In essence, the defining characteristic of a contract of adhesion is its one-sided nature, which makes it the correct answer in the context of the question about bargaining power and restrictions.