The Amazon Queen of Themyscira and Diana's mother. After meeting the director for the role, Nielsen said, "Patty and I met in London, and we just hit it off from the get-go. We couldn't stop talking. What was supposed to be a one-hour meeting turned into a two-and-a-half-hour lunch and we just really got each other." She described Jenkins's directing style for the film as "She's also the kind of director that I really flourish under. She has very strong and particular and specific ideas about what it is she wants to say. She comes from a place of strength always. And so, when you are dealing with someone like that, you feel absolutely free to be vulnerable, to be creative, and I am a big researcher." On playing the character, Nielsen said, "It was a complete and utter pleasure and I absolutely loved every second of playing her." On her character being Diana's mother and Amazonian queen, Nielsen stated, "I'm queen and I'm preparing my child for a world that entails a lot of responsibility. So it was important to me to bring that into the character." She read The Amazons by Adrienne Mayor to familiarize herself with women warriors and said "I used what I learned in Mayor's book as a rallying cry for how I approached Hippolyta. And then, of course, what is a leader who is elected by her peers every year and has been doing this for a thousand years? That too was interesting to think about". Nielsen went through a workout regimen for the film, saying "I did six hours a day. You know, two hours of weight training, two hours of swords training, and then two hours of horseback riding".
"Gas was intended to win the war. On that much Wonder Woman is absolutely right." said David Hambling in Popular Mechanics. Rachel Becker of The Verge stated that despite the scientific liberties of using a "hydrogen-based" chemical weapon as a plot device, the film succeeds in evoking real and horrifying history. "First off, mustard gas is such a horrible, terrifying weapon, it doesn't need to be made more potent. But if you were a chemist bent on raining destruction on the Allied forces, you wouldn't do it by replacing the sulfur atom in mustard gas with a hydrogen atom. You'd know that sulfur is the linchpin holding together this poisonous molecule."