Why go
A plate of pork or beef with dumplings tells you more about traditional Czech cooking than a generic restaurant list. Fruit dumplings, or ovocné knedlíky, show that dumplings can also be dessert. The Old Town Square and Wenceslas Square offer convenient breaks during sightseeing, but convenience alone does not tell you what a meal will cost.
The full story
Make lunch the meal to plan around if you want to try traditional Czech food. Pork or beef commonly comes with a filling side such as dumplings or potatoes. If you would rather keep walking, the Old Town Square and Wenceslas Square have long been the obvious places to look for a quick bite; treat any particular stall as a current choice to check on the day. For dessert, look for ovocné knedlíky, fruit dumplings that make a different finish from a cake or ice cream. In the heavily visited streets near the river and Prague Castle, read the menu before ordering and check what is included in the price. If bread, condiments or a cover charge appear on the bill and the terms are unclear, ask the server to explain them before paying. For a specific restaurant, confirm its current menu, opening times and booking arrangements directly with the venue.