Puzzles

You may encounter many different puzzles hidden around the dungeon:

Pedestal Puzzles
The most common puzzle is a locked door surrounded by four pedestals that have either: The solution to solve the puzzle is to either remove the key, or remove every item except the key. You'll need to search the level (or surrounding levels) for details on which key to remove or retain. The information is often to be found on a sign, sometimes in a book. Rarely a white circle may appear somewhere that gives you a hint to look in a secret room, this is a message from one of the gods.
 * Four animals in different materials (e.g. gold, amber)
 * Four different marble animals (e.g. bull, owl)
 * Four different marble shapes (e.g. circle, triangle)

Books containing information about the key may refer to a riddle as to what the key is, or tell you to look in a library on a different floor, when in that library (or if white circles tell you to go in a secret room), look around for carpets, statues, signs and books which may tell you the key. For example: a carpet with squares, a statue of an owl, a book about monkeys, or a sign saying 'The key is made of gold', the number of jade cats shows the number of corners the key has.

The information of whether to remove the key or everything except the key, will always be found in a book. Note that books displaying information are not always on the same level as the puzzle, they may be one level above or below. Some times the book can be in shallow water, if it is dark water it may be hard to see it.

When you have these 2 pieces of information, you are ready to solve the puzzle.

If you remove something and the door does not open/turn to stone, it means that you have to remove everything except the key. If you accidentally removed the key in that case, putting it back on and removing everything else does NOT work. After removing 2 items in that case, the door with lock up.

Empty Pedestal Puzzles
A variant on the locked door pedestal puzzles, these are more difficult. You'll need four different items which may be marble animals, different material shapes or different material animals. All of these items are not necessarily found on the level with the puzzle.

The information you need is: Similar to the first puzzle, signs and books often give a clue to what you need to put on the pedestals.
 * Which pedestal to place one of the statues on, and
 * Which statue you need to put on the pedestal

To find out which pedestal you need to place the statue on, you need to find a book with a potion or scroll, the book explains what to do, if you find an unidentified potion or scroll next to a book, the book will almost always say what it does, you need to either throw the potion at the pedestals or read a scroll nearby. A symbol appears on the correct pedestal. An example of this is where the clue will indicate that the correct pedestal will be revealed in darkness. In this case, you will need to read a Scroll of Darkness near the pedestals (normal darkness will not work). Other times you have to use a scroll of light. Other times you need to fill the room with one of many gasses.

To complete the puzzle, place the correct item on the pedestal.

Bell Puzzles
These ones recently appeared in the dungeon and consist of four bells that play different tones when rung. There are no books or signs giving information about this puzzle and you can not fail it. You must simply ring the bells from lowest to highest tone.

Clay Statues
Sometimes in a level, you may find some clay skulls or clay wolves around. Books will often provide information what to do with them. Sometimes you have to throw them in a certain room, sometimes one of them contains a key that you need. Only start throwing them if you know what to do with them because if you need to throw one in a certain room and you've thrown all of them outside that room, you can't beat the puzzle.

The Sphere
Sometimes you find a book together with a sphere, the book tells you to (not) throw the sphere in a Myst filled hall on a certain floor for a reward, you indeed get a reward for throwing it but the sphere also triggers a magic missile explosion in the Myst, so make sure to immediately leave after throwing the sphere to not take needless damage, then just come back after the missiles are gone.

Screaming Skull Key
A book tells you that someone hid a key in a screaming skull. What you need to do is walk around the level, kill some skulls and then throw the skull that drops for the key. If the skull doesn't contain the key, it will come back to life after throwing it.

Heartless Ogre
You can't defeat the heartless ogre without throwing its heart in the lava, just look around the level for a living heart and lob it in there, then you can go kill the ogre. There should always be a secret room containing some lava on the level.

Pressure plates puzzle.
You have 4 plates than need to be pushed to spawn a chest. Some times you only need to push 2 or 3 and the other ones will be traps.

Fire Brazier puzzle.
2 ore more unlit braziers, lighting them up will reveal a hidden room or open a locked sarcophagus or spawn a chest.

Sprite Puzzle.
Catching white or red sprites and releasing them in a Grievous (red) or Sophie's (white) room may give a reward.

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(Credit to pimhazeveld for providing this awesome write up here: https://www.reddit.com/r/unexploredgame/comments/6pg15b/everything_you_need_to_know_about_puzzles/)