The board of governors for the Academy of Motion Picture Arts and Sciences increased the number of nominees to five, up from three, at the 83rd awards show next Feb. 27.
The switch brings more awards attention to visual effects, which play a bigger role in Hollywood blockbusters as digital-animation technology continues to advance.
Since 1996, the visual-effects category has featured only three nominees, including last year's winner, the science-fiction blockbuster "Avatar."
The academy also announced Thursday some changes to the feature-animation category, including shortening the minimum running-time for animated contenders to greater than 40 minutes. That's down from the previous minimum of 70 minutes.
The change brings the animation rules in line with the minimum running times in other feature-film categories.
The new rules include language to clarify what constitutes an animated film, stating that "motion capture by itself is not an animation technique."
Motion-capture records performances by live actors wearing special suits covered with sensor dots that are read by digital cameras. The technology was used as the foundation for alien characters in "Avatar," the great ape in "King Kong" and the Gollum character in "The Lord of the Rings" films.