No more of this.

Diehard comic-fan types like making an event out of seeing movies — Harry Potters, Spiderman or Batman flicks, for example — by dressing up in costumes.

Nerdy, yes, but good fun.

Because of the event a few nights ago — in which a masked man killed 12 Aurora, Colorado moviegoers — AMC Theaters, including all in Dallas, has banned costumes.

The shootings, by the way, happened at a Cinemark. Cinemark may or may not follow suit. No official word.

In addition, Dallas police have announced that they will up security in public gathering spaces such as movie theaters.

“In response to the shooting that occurred in Aurora, Colorado, the Dallas Police Department has instructed patrol officers to provide extra visibility and to be extra vigilant at public locations where large numbers of people gather, such as movie theaters,” according to an announcement. “The Dallas Police Department does have plans and procedures in place to quickly and effectively respond to incidents of this nature. Police officers have been receiving training for several years on how to respond to an incident involving a person who is actively firing a weapon in public buildings.”