It require sufficient voltage to overcome skin resistance, and then enough current (amperage) to damage the heart. It varies but it really isn’t very much. With high voltage there is a lot of burning, but with household type currents there is usually death without much burning. Poorly grounded washing machines on wet concrete floors are a common cause of household electrocution.
I have a high skin resistance and have quite genuinely lost count of the number of electric shocks that I have had. Usually as a result of working on live equipment – it is often easier and faster to get results that way.