I actually did that my first time playing King's Field The Ancient City. I took probably 5-6 steps, "well this ground looks a little different." and cracked through it to meet my lava demise.
This little voice told me "Welcome to King's Field". HA!
I'm not sure the exact number of steps, but its certainly a single digit of them.
I miss this game, but I don't have it anymore. >_<
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Did something similar on King's Field Additional II. The absolute first fatal fall in the game I fell - about 45 seconds into the game.
Welcome to King's Field!