Encumberance

This spell causes a creature or object that you can see within range to become supernaturally heavy. This spell has two effects, depending on what you target with it.

An item you target with this spell must fit within a 5 by 5-foot area and cannot be an artifact. Casting this spell on an object causes it's weight to double, and on each of your turns for the duration, you can use your action to cause the item's current weight to double again. The spell ends if you use your action to do anything else. The spell also ends if the targeted object is ever outside the spell's range or if you cannot see it.

A creature you target with this spell must make a Strength saving throw. On a failed save, their weight is doubled and their movement speed is reduced by 10 feet. The target can repeat this saving throw at the end of each of their turns, ending the effect on itself on a success. Every time the target fails the saving throw, their weight doubles again and their movement speed is reduced by an additional 10 feet. If the creature fails the saving throw while they have 0 movement speed, they instead gain disadvantage on ability checks and attack rolls that use Strength or Dexterity. 

Once an object or creature has been effected by this spell, they cannot be effected by it again for the next hour.