1) Mix the flour, salt, cream of tartar with a whisk until well blended. Break up any lumps of salt with your fingers.
2) Add the oil to the hot water (a good job for grownups). Mix into the flour blend until a smooth dough forms. The dough will be quite warm to begin with, but cools quickly.
3) If using colors and scents, divide the dough into sections and scent and color each. Wearing rubber gloves for the initial kneading will help keep your hands from becoming stained.
4) Once your shapes, critters, and designs are done, they can be dried at room temperature overnight, or longer, and painted with craft paints for lasting treasures. If you are not keeping shapes, etc. the playdough can be stored airtight in the fridge for one week.