Many people confuse these two very popular games. While they do have similarities – they both involve finding something – they are very distinct.
Explanations of the differences will tend to focus on the value of the items to be found. Treasure sounds like it should be something valuable while a scavenger might be searching for items that others have discarded.
Alternatively, the number of items that are to be found is highlighted. A scavenger hunt is based on a list of items whereas there is only one treasure.
We feel that Laureen Brunelli is closest to the mark in her article Scavenger or Treasure Hunts for Kids.
A treasure hunt is when a series of clues leads kids to a “treasure.” … A scavenger hunt, on the other hand, is a search for a list of items.
Zach Lazzari also has some good stuff in Treasure vs. Scavenger Hunts.
The key is that treasure hunt riddles form a sequence that lead to a treasure. Each riddle must be solved in turn to make any progress. A scavenger hunt has no such restriction with participants being free to cross items off their lists in the order that is most convenient.