Elder runes are ancient symbols imbued with magical power. With years of study, any creature that can cast the symbol spell can learn an elder rune and add it to the selection of symbols that can be created with the spell. Halaster has spent lifetimes studying elder runes, inventing new ones, and harnessing their volatile magic. He likes to place them throughout Undermountain as hazards.
Appendix B presents several elder runes on paper cards that you can photocopy and cut out to create an Elder Runes Deck. When circumstances call for the appearance of an elder rune, a card is drawn from this deck to determine which rune appears and what it does.
Elder runes function as symbols cast using the symbol spell, with these changes:
- An elder rune has two possible effects: one beneficial (called the boon effect) and the other harmful (called the bane effect). The elder rune's creator chooses which effect occurs or can randomize it so that a die is rolled to determine whether the bane effect (odd die roll) or the boon effect (even die roll) is triggered.
- A triggered elder rune targets one or more creatures within 60 feet of it, according to the caster's specifications. Once the effect activates, the elder rune disappears and the spell ends.
A creature doesn't make a saving throw against an elder rune's boon effect. Saving throws made to resist the bane effect of Halaster's elder rune have a spell save DC of 22.
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