Induction vs Gas Cook Top
From the FAQ on the All-Clad website:
1. Is All-Clad cookware induction-safe? What is induction?
Induction range tops do not have combustible or open flames, but use a magnetic field to create heat. The technology is widely used in Europe and is popular in professional kitchens because it is so efficient. All-Clad Stainless has been induction-ready since its development because we use a special magnetic stainless steel on the exterior. We built the Stainless collection to be used on any stovetop and in professional kitchens that have adopted this technology."
You can do the "magnet test" on cookware. If a magnet sticks to the pot then you are good to go. If there is a specific piece that you can't part with, you can get an induction interface disc so you can still use that favourite pan.