Why does SLICE sometimes create an unexpected result on a 3D solid?

[indiancad]

Have you ever used SLICE on a 3D solid and ended up with a cut that wasn't where you expected?

I ran into this when the cutting plane was not aligned with the part the way I thought it was.

Before slicing, I found it useful to check the current UCS and viewing direction, then define the cutting plane carefully using 3 points or an existing planar object.

I also make sure I'm selecting the correct side to keep after the slice.

A quick UCS/view check can prevent a lot of unnecessary editing afterward.

When SLICE gives an unexpected result, what do you normally check first?