So the thought of Kasia falling down our staircase is one to fill our hearts with dread, because it would be way worse than just falling down carpeted or even normal wood or linoleum stairs.
Mary, realizing that we had to convey the danger to Kasia in a way she could understand, decided on an object lesson. She took an egg out of the fridge, carried it to the top of the stairs, and explained to Kasia the similarities between the egg and Kasia's noggin. Satisfied that Kasia got the analogy, Mary proceeded to toss the egg over the babygate and we watched as it went "splat" on the stairs. "Do you understand now?" Mary asked. Kasia nodded gravely.
Then Kasia solemnly proceeded to the fridge to get another egg so that she might participate in the apparently very serious, albeit mysterious, 'Egg over the Stairs' ceremony. Which was not exactly where we were going with this....
Kasia is a much more cautious child than Tigana ever was, but far more tenacious, so is sometimes harder to dissuade from dangerous course of action than was Tigana. This same demo worked successfully with Tigana at that age -- she totally got that if you fell from the stairs you died. Of course, in Tigana's case we found her hanging off the banister over the atrium (of our previous house) two days later, and when I asked had she not understood the danger, she somewhat cavalierly explained that even if she fell, she had two more lives to go. Shocked at this reply, I inquired what gave her that idea, and she explained how on the videogames at Daycare you always had three lives, more if you did well.... "So if I die, I'll just start over as a baby again, right?" Fortunately, Mary pointed out that althougth that may well be true, there was no guarantee that she would be coming back as our baby... that she only got one shot at being 'Tigana' and next time round she would be someone else's kid, probably in another part of the world.... Tigana has been more respectful of heights ever since...