Generally something that can be deterministically scripted to work around won't work well as a captcha: https://imgur.com/a/mbLnTH7 https://imgur.com/a/mbLnTH7

Generally something that can be deterministically scripted to work around won't work well as a captcha: https://imgur.com/a/mbLnTH7 https://imgur.com/a/mbLnTH7 Here I'm just clicking the entire row of pixels four times. Even if you fixed that (perhaps misses could trigger a failure), then you still need to create a problem that's hard for a computer to solve .. finding the monster seems pretty straightforward.