Where the language in a contract must be in plain English that most people can understand.
That should help prevent people being dropped because of hidden or ambiguous clauses.
Contract law also requires that there be legal consideration, where someone can't create a contract where only one benefits and the other party doesn't.
That is already largely illegal.
Contract law is a fun topic (in my opinion), you should check it out.
Consideration - Wikipedia, the free encyclopedia
Contract - Wikipedia, the free encyclopedia