When you make a saving throw and take damage, you can take a Reaction to use your XPHB, halving the damage you take (round down).
Spider Sense
Raw data
{
"name": "Spider Sense",
"level": 13,
"__prop": "subclassFeature",
"header": 2,
"source": "ValdaPlayerPack",
"entries": [
"When you make a saving throw and take damage, you can take a {@variantrule Reaction|XPHB} to use your {@classFeature Uncanny Dodge|Rogue|XPHB|5}, halving the damage you take (round down)."
],
"className": "Rogue",
"classSource": "XPHB",
"subclassSource": "ValdaPlayerPack",
"subclassShortName": "Arachnoid Stalker"
}