There are several types of items across Jadame that have special functions. Some are covered in your manual but deserve additional treatment here. You need to be aware of their uses to follow some of the tips that appear under other topics.
Most Wells (and Fountains, Troughs, etc.) in Jadame do something. Most of what they do is beneficial, but not always. There are Refill Wells that replenish either Hit Points or Spell Points. Other Wells boost a character's Attributes (ie, Primary Statistics) either temporarily or permanently. Some Wells do things that you won't be aware of immediately and others will give your character an adverse condition. You may want to save before testing one, or you may choose to play out the consequences.
You'll come across various Spell Pedestals in your travels. Touching them casts a Spell on your entire party. The Spells are cast at Grand Master 5 and take precedence over Spells previously cast.
Barrels grant a +2 boost to one of the Attributes, aka Primary Statistics. The color codes will be recorded in your Autonotes. Cauldrons will either produce food or grant a boost to one of the Resistances.
With a high enough Perception value, Fires and Campfires will typically produce a piece of jewelry. Trash Piles typically produce a weapon or piece of armor, but they also bestow the Poisoned or Diseased condition to most characters.
The Braziers will award Skill Points to a character who has an Attribute value equal to or higher than a certain number. Games require a value of 25, Contests 50, Tests 100 and Challenges 200.
Obelisks give clues to a treasure hunt. The inscription from each one will be recorded in your Autonotes. Once you've clicked on all 9 Obelisks and deciphered their code you can go about pursuing the treasure.