# Lance of Lethargy *Source: Xanathar's Guide to Everything p. 57* **Prerequisite**: [eldritch blast](/Rules/Source/spells/eldritch-blast-xphb.md) cantrip Once on each of your turns when you hit a creature with your [eldritch blast](/Rules/Source/spells/eldritch-blast-xphb.md), you can reduce that creature's speed by 10 feet until the end of your next turn.