There was a swear jar on the set. Co-writer and director Gary Ross said half of it was contributed by Jennifer Lawrence.
While horsing around on the set, Jennifer Lawrence accidentally kicked Josh Hutcherson in the head, knocking him out and resulting in a concussion.
Jennifer Lawrence was paid what was, for her, the high fee of $500,000. It took her three days to accept the role because she was unsure how it would affect her career since her background was mainly on the indie film circuit. For The Hunger Games: Catching Fire (2013), she was paid $10 million, twenty times the initial offer.
Donald Sutherland saw the script by accident, and after reading it, he lobbied for the role of President Snow because the script reminded him of Stanley Kubrick's Paths of Glory (1957). He wrote a letter of plea to the director Gary Ross, explaining what the character of Snow meant for the narrative and why he should be cast. It worked, and Ross was so impressed by Sutherland's insights that he wrote two scenes into the script based on what Sutherland had written.
Panem is in a post-apocalyptic North America that was devastated by nuclear wars and climate change, leading to severe droughts, storms, and fires that made large parts of the land uninhabitable. Due to a subsequent rise in sea levels, significant parts of its eastern and western coastlines have disappeared, causing a severe reduction in land mass. Since Washington was flooded, the country's administration had to be rebuilt elsewhere, and it is generally agreed that the current Capitol is in the Rocky Mountains, roughly within the former area of Wyoming and Utah. District 12 town, where Katniss grew up, is in the Appalachian Mountains, possibly Kentucky or West Virginia.