Infocom introduced (AFAIK) the concept of feelies:
[…] Imaginative props and extras tied to the game’s theme—provided copy protection against copyright infringement. Some games were unsolvable without the extra content provided with the boxed game. And because of the cleverness and uniqueness of the feelies, users rarely felt like they were an intrusion or inconvenience, as was the case with most of the other copy-protection schemes of the time. Feelies also provided the player with a physical aspect to the gameplay of their text adventures, giving another dimension of strategy to what would other-wise just be a text parser.– Wikipedia (Infocom)
I love to give out feelies for my D&D campaigns. Here are some lil handout props I made:
I used a receipt printer, q-tips, tape, and orthodontic rubber bands.