Willard Huyck and Gloria Katz, based on a story by George Lucas
George Lucas loves sequels as much as Anakin Skywalker hates sand. So it's not a surprise that after the success of Raiders of the Lost Ark, George Lucas wrangled Steven Spielberg into a sequel.
Lucas wanted to use many ideas that were left on the cutting room floor of Raiders, alongside the skinless skeleton of Major Toht. Among these scenes were the wild mine cart chase and the bonkers skydiving raft sequence. (Source)
But you need a…oh…what is it called? That's right: a plot. That's critical to tie these things together. Lucas attempted to get Raiders screenwriter Lawrence Kasdan back into an Indiana (Jones) state of mind. Although Lucas convinced Kasdan to strike back for both Empire and Jedi in the Star Wars universe, Kasdan passed on Temple of Doom. Kasdan said the film was "very ugly and mean-spirted." (Source)
Ouch, Larry. Tell us how you really feel.
After having his heart metaphorically torn out by Kasdan, Lucas recruited the dynamic duo of Willard Huyck and Gloria Katz. This husband/wife pair wrote Lucas's American Graffiti. For "Indiana Jones and the Temple of Death," as it was then called, they took inspiration from Gunga Din.
Gunga who? Gunga Din is an 1890 poem by Rudyard Kipling, which inspired a 1939 film. The film followed three British soldiers in India during the Thuggee uprising, making it a spiritual predecessor to Temple of Doom. (Source)
It also explains Doom's imperialist undertones. Lucas, Huyck, and Katz also borrowed a musical sequence from their still-in-the-planning-stage film Radioland Murders to open Temple of Doom. Hey, whatever pays the bills.
Huyck later wrote and directed one of the greatest flops of all time: Howard the Duck. That's a bill no one asked for…although the Duck did make a cameo in 2014's Guardians of the Galaxy. (Source)