Difficult Terrain doesn't cost you extra movement. Allies that can see you within 120 feet of you also gain this benefit.
Lead from the Front
Raw data
{
"name": "Lead from the Front",
"level": 7,
"__prop": "subclassFeature",
"header": 2,
"source": "ValdaSpire24",
"entries": [
"{@variantrule Difficult Terrain|XPHB} doesn't cost you extra movement. {@variantrule Ally|XPHB|Allies} that can see you within 120 feet of you also gain this benefit."
],
"className": "Warmage",
"classSource": "ValdaSpire24",
"subclassSource": "ValdaSpire24",
"subclassShortName": "Kings"
}