EU regulation 261 (2004) requires airlines to compensate passengers between €250 and €600 cash for flight delays of over 3 hours, for cancellations, and for involuntary denied boardings due to overbooking. The amount depends on the distance of the flight.
This applies to flight departures from EU countries, and it applies to flights headed to the EU on airlines based there. It also includes Iceland, Liechtenstein, Norway and Switzerland. And it applies to award tickets not just paid tickets.