Solid Stance
You are difficult to move or knock down.
Preqrequisite
Con 15.
Benefit
Once per combat when an attack or effect would knock you prone, you can ignore that effect as a reaction. In addition, the distance that any nonmagical effect that would move you against your will is reduced by 5 feet.
Source
Character Operations Manual pg. 118
Dragonscript
ID
dd6cca1b22f8cf33a657d9c6
Preqrequisite
condition character.constitution >= 15;