Action films feature heroes who engage in physical challenges and fights against formidable opponents and odds. These films involve life-threatening situations, villains, or pursuits that conclude with the hero's victory. Some of the earliest action-based films in the 1920s and 1930s involved sword fighting in period films or Westerns, while war and cowboy films of the 1940s and 1950s incorporated more action sequences. The genre became more defined and popular in the 1970s and 1980s with the rise of stunt work and special effects in films like the James Bond franchise.