In last week’s post on Breath Weapon Dice Pools, I suggested that you could power up the breath weapon by allowing the dragon (or other monster) to charge their breath weapon beyond its normal limits. This week, I’ve developed an overcharge system to drive more dynamic combat. We’ll be using the Breath Weapon Dice Pools for this exercise, so if you missed last week’s post or need a refresher, go check it out now.
A dragon (or other breath-weapon-toting monster) can overcharge its breath weapon. It’s up to you whether this occurs naturally upon recharge, whether the dragon can choose to do it, or whether its a product of some environmental effect. For example, maybe a blue dragon is struck by lightning or a red dragon dives into lava to overcharge their breath weapon. Or the party hits the dragon with an appropriate elemental attack.
Remember to tip your players narratively by describing how the overcharge affects the dragon. Using an environmental effect to set this off can help add to the narrative, and alleviates questions of what happens to a dragon who is constantly overcharging.
Install a cap on the overcharge. I recommend setting the overcharge cap at one recharge (1/3 above total breath weapon dice). This keeps the breath weapon damage from getting too out of hand. It also keeps you from having to account every turn once the breath weapon is (over)charged.
This is where the fun comes in. When a breath weapon is overcharged, it may affect the dragon in other ways. I’ve developed a table of effects that you can roll on, use as inspiration, or tie to specific damage types. These effects are simple to employ because they use the statistics of the breath weapon. They use the same DC and damage type as the breath weapon. One caveat is that any effect that deals damage to the dragon itself has to be modified, since dragons don’t take damage from their breath weapon type. So, we turn to old reliable: force damage.