Saving

"'One must save their progress in order to preserve data.'"

World of Doug RPG (Save Symbol)
Saving in World of Doug RPG happens when you draw a symbol of Mnemosyne known as the Save Symbol. The Save Symbol can either recover your HP, SP, and sometimes it can give buff all of your party members but it only depends on what materials you use to draw a symbol on.

World of Doug: After Story RPG (Save Diary)
After defeating Mnemosyne you get to use the Save Diary, a consumable item. 200 of them can only be used once, 50 of them can be used 5 times, 5 of them can be used 20 times, and 1 of them can be used an unlimited amount of times.