Civil Procedure I

Forum-selection clauses say where a contract shall be litigated to the exclusion of all other courts.

Prima facie valid and enforceable
...unless one of:

Obtained by fraud, undue influence, overwhelming bargaining power
Application would render litigation so gravely difficult and inconvenient that for all practical purposes plaintiff would be deprived of day in court
- Second is basically fairness factors

Reference: Paul Business Systems & Carnival Cruise