Shops

There are various shops and services in the world, each with their own use. In order to buy something from the shop, drop whatever it is the shopkeeper wants in front of them, and press 'tab' a few times to skip turns until they pick it up. If they have multiple items to sell for the same price, a dialog window will pop up asking you to select whatever you want. The shopkeeper will then drop the item you want so you can pick it up. In some cases, where shopkeepers provide a passive bonus (e.g., upgrading your health), you will not have to pick anything up.

Overview
1it is possible that this does not affect items stored in your portable chest.