An energy node is a particularly strong confluence of arcane, divine, and other forms of power. The air above it shimmers with energy, and anyone standing upon it feels fresh and reinvigorated.
Effect: A creature that starts its turn in an energy node’s square can spend a minor action while in the square to regain a single encounter or recharge power. Using a node for this purpose depletes its energy, and it can’t be used again until 24 hours have passed.
Usage: Energy nodes work well in long, running battles and in encounters with solo monsters. Not only do they allow the characters (and monsters) to use encounter powers multiple times, but they also create a situation in which the player characters might be racing against their opponents. Only one creature can benefit from each energy node, forcing the characters to fight for access to any nodes in an area. In a fight against a solo monster, consider placing more than one node around the perimeter of the encounter area, or in hard-to-reach places, which can force PCs to disengage in order to draw upon the power of a node.
Published in Dungeon Master's Guide 2, page(s) 59.