In Switzerland, employment contracts may include a clause that prohibits you from working for the competition for a while after leaving the company. It is called "prohibition of concurrence" (in French, "clause de non-concurrence"; in German, "Konkurrenzklausel"), and is regulated in articles 340 to 340c of the Swiss Code of Obligations. What many do not know is that this clause has precise legal limits, and that it is not always worth what it puts on paper.
For the clause to be valid, several conditions must be met. First, it has to be signed in writing: a verbal clause does not exist in Switzerland. Second, the employee must have had real access to trade secrets or to the company's clientele, so that moving to competition could cause real harm to the employer. If you worked in a position with no contact with customers or sensitive information, the clause may be challenged. Third, the duration and geographical scope must be proportionate: Swiss law sets a maximum of three years, and courts often shorten deadlines they deem excessive.
What surprises those who do not know: if it is the employer who fires you without valid cause, the attendance ban automatically falls. This is in article 340c Co. The same applies if you leave for good cause, for example, because the employer has seriously breached the contract. In practice, many non-compete clauses that appear shielded cease to be shielded the moment the employer takes the first misstep. Some people discover this too late, when they have already accepted a lesser job for fear of a clause that did not really apply to them.