Starting at 10th level, when you cast an enchantment spell of 1st level or higher that targets only one creature, you can have it target a second creature.
Split Enchantment
Raw data
{
"name": "Split Enchantment",
"page": 117,
"level": 10,
"__prop": "subclassFeature",
"header": 2,
"source": "PHB",
"entries": [
"Starting at 10th level, when you cast an enchantment spell of 1st level or higher that targets only one creature, you can have it target a second creature."
],
"className": "Wizard",
"classSource": "PHB",
"subclassSource": "PHB",
"subclassShortName": "Enchantment"
}