Play is what is known as a treatment, a regular patterning, usually over the whole background of the shield. The word comes from the pale, the major vertical stripe that appears on some shields, paly is obvious its little cousin, consisting of, typically, 6 or more vertical stripes, alternately coloured A Glossary of Terms used in British Heraldry, J.H. Parker, Oxford, 1894, Entry:Paly. The stripes can be any combination of the heraldic tinctures, an early example is that of GURNEY, being simply paly of six, or and argent. Paly can be combined with other effects, such as decorative edges on each stripe, or overlaid with other treatments such as bendy, and these can be very effective and pleasing to the eye A Complete Guide to Heraldry, A.C. Fox-Davies, Bonanza (re-print of 1909 Edition), New York, 1978, P121.