A death-first search is when you lose your keys and travel to the depths of hell to find them, and then if they're not there you start checking your coat pockets.

"Depth and Breadth", by Randall Munroe, licensed under Creative Commons Attribution-NonCommercial 2.5 License

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A death-first search is when you lose your keys and travel to the depths of hell to find them, and then if they're not there you start checking your coat pockets.