§1.5. The Replay button
Replay works identically to Go, except that it does something further: once the game is created, it automatically plays through the same commands as were typed into the previous version. For instance: suppose we click Go to bring Midsummer Day into being, and find ourselves playing the game. We type "look" and find that there is not much to see. Going back to the source, we add
"A white canvas parasol raised up on stakes driven into the grass."
so that the source now reads
The Gazebo is a room. "A white canvas parasol raised up on stakes driven into the grass."
Instead of clicking Go, we click Replay, and can sit back and watch what has changed. In this example, it only saves us the trouble of typing "look", but once games become long and elaborate, Replay is invaluable: and especially when we notice in play that something very minor is wrong - a spelling error, say - and want to fix it immediately, without fuss.