Article: In 1978, Jim Shooter became Marvel's editor-in-chief. Although a controversial personality, Shooter cured many of the procedural ills at Marvel, including repeatedly missed deadlines. During Shooter's nine-year tenure as editor-in-chief, Chris Claremont and John Byrne's run on the Uncanny X-Men and Frank Miller's run on Daredevil became critical and commercial successes. Shooter brought Marvel into the rapidly evolving direct market, institutionalized creator royalties, starting with the Epic Comics imprint for creator-owned material in 1982; introduced company-wide crossover story arcs with Contest of Champions and Secret Wars; and in 1986 launched the ultimately unsuccessful New Universe line to commemorate the 25th anniversary of the Marvel Comics imprint. Star Comics, a children-oriented line differing from the regular Marvel titles, was briefly successful during this period.

Now answer this question: Secret Wars was an early example of what Marvel comics story trope?
crossover story arcs