24 Mind-Blowing Facts About 24

13. Most Phone Calls Were Filmed With The Other Actor On The Line

24 was ground-breaking in many areas, and a minor one you probably don't know about is that it was one of the first shows (and remains one of the few) to actually film phone calls with the other actor present. Typically a script supervisor or random crew member will feed the actor the other character's lines, but where possible, given how many phone calls Jack makes in a single episode alone, the other actor would be speaking directly to Kiefer Sutherland, or actually be on the other end of the phone. Obviously it hasn't been possible 100% of the time due to logistical issues, but the majority of the phone calls aren't pretend as they are in most shows and movies. It adds a little more nuance and believability, and of course makes things much easier for the actors.