In the Book One you get to control three characters: Tom the Master Builder, Friar Philip, and Jack, a youth brought up in the forest. The two latter ones have their unique items – the Bible and a slingshot, which can be used on other characters and interactive objects. When it comes to Jack, in some situations it is even necessary for the plot to continue or to get an achievement.
When pointing at the active objects, the cursor turns into a dot surrounded by a white circle. If the left half of the circle is faded, while the right one is clear orange, it means that after several RMB clicks our character will make some remarks on a given object, however he will not interact with it.
All the active objects become visible after you click space bar or the scroll button on your mouse. By clicking the direction cursor twice, you will speed up the character.
Apart from the items that you obtain for your inventory, the game also features certain additional items that end up in the ‘Documents’ tab (visible in the menu options) and broaden your knowledge on the characters, story background, and the plot itself.
During the game, you will acquire so-called clues (mostly, as a result of conversations), which appear in the inventory on the bottom of the screen, similarly to the objects you collect (these are visible to the right of the inventory). The clues can (and sometimes have to) be used on certain objects and characters.
During nearly every dialogue, you have to make decisions that are mutually exclusive. Sometimes, you can hold yourself off answering. In such cases you will see, how the white circle with possible dialogue options features a disappearing white bar – if you do not click any option in time before the bar vanishes completely, a matter will not be settled. In most cases, the choices you make have certain consequences – from the attitude towards your character to alterations of the plot resulting in e.g. skipping a part of the chapter.
The game does not feature any environmental puzzles, neither the ones in which you have to join items or split them into smaller elements; nonetheless, there are occasional arcade minigames. They require good reflex, since you have to click LMB when the white circles, moving right and left at different speed, cover the celadon fields. In most cases, these sequences are not difficult, however sometimes the circle can move really fast.
By default, there are two interface options turned on: ‘Show the diary’ and ‘Show the progress’. If you do not want to see the current task and the location name (top left corner of the screen), as well as the information which Book and Chapter are you playing (bottom right, after hovering over with your mouse), you can turn them off in the options menu.
In the Book One there are 21 achievements to acquire, however only a small portion of them can be completed by simply following the plot. In most cases, they require a more careful exploration, consistent story-related decision, and sometimes even complete passivity. Some of the achievements are mutually exclusive.