"Tougher rules" refer to stricter or more stringent regulations or guidelines that make something more difficult, strict, or challenging to comply with or follow. Full definition
However, one crazy fan stood out who listed out really tough rules for his girlfriend if she wanted to join him at the screening. (indianexpress.com)
What happens when a community decides that the statewide building code doesn't go far enough and adopts a newer version of a model code with tougher rules on energy conservation? (greenbuildingadvisor.com)
The temptation to win «by any means» will always be there, and so tough rules need to be in place. (canadianbusiness.com)