An engineering intensity scale is proposed for earthquakes and for ground motion resulting from nuclear or chemical explosions. It is based upon 5 per cent damped response spectra developed from the ground motion and a standard 10 × 9 matrix with columns representing period bands and rows representing prescribed response velocity levels, Sv. Acceleration or relative displacement can also be readily assigned with the use of 4-way logarithmic paper. The El scale can be reported by period column as 9-digit, 3-digit, or 1-digit numbers, or by all three in a standard format. The more digits reported, the greater the amount of information on the period bands. The advantages over existing scales are many including ratings that are directly informative and useful in damage estimations and which ratings are made objectively and have period identification lacking in other scales. Some example El ratings are provided.