This group of dark patterns goes beyond pressure. Users are (de facto) forced to conduct or to acquiesce an action in order to perform another.
The Forced Enrollment dark pattern makes the use of a service dependent on the acceptance of further conditions. However, these are not actually required for the provision of the service.
In this example, no further activities can be performed without signing in or creating an account, even so the desired content is already visible in the back.
The Forced Continuity pattern automatically renews free or low-cost trial subscriptions - but for a fee or at a higher price. The design trick is that the order form visually suggests that there is no charge and conceals the (automatic) follow-up costs.