An implicational scale is a set of lexical items that are

• of the same constituent category, and
• ordered in terms of their informativeness.

Any sentence including one item of the set entails all of the propositions expressed by similar sentences containing less informative items. In addition, in keeping with the quantity maxim, the use of an item in the scale creates scalar implicatures that disallow the propositions expressed by similar sentences that contain more informative items.