The wearer of Seven League Boots can traverse up to 21 miles in the time it takes to take a single step. However, the wearer will be just as tired as if they had actually walked the entire distance without stopping, and so suffer the Affliction “Fatigued” (-3 on all Ability Checks) until they can get a full night’s rest.

If the wearer tries to use the magic of the Boots a second time in a single day, they must Save versus Constitution or be reduced to 0 Hit Points (and thus fall down completely incapacitated) at the end of their journey.

If the wearer avoids becoming incapacitated, and tries to use the Boots a third time in a day, they must save versus Constitution or die from exhaustion at the end of their trip. If they survive, they must likewise Save or die with every seven-league step attempted thereafter, until the wearer has had a chance to sleep.

Remember that all Constitution Saves made after the taking first step are made with a -3 Penalty from being “Fatigued”.