Converting Wyvern stings

[bedir than]

The standard wyvern stings with a poison attack (+7, reach 10, 2d6+4 w/ DC15 poison v 7d6 damage halved on save). This is a fairly potent attack, but can be repetitive and weakened against certain character builds (or as the party learns how to neutralize poison).

Would there be any damage to balance (effecting CR) if that stinger was replaced with other damage types. I'm thinking of a wyvern that stings and does Shocking Grasp, or Fire Bolt, Ice Knife or other cantrip type effects within the sting. They'd do similar type of damage, but have a changed damage type.

 

[dave2008]

The standard wyvern stings with a poison attack (+7, reach 10, 2d6+4 w/ DC15 poison v 7d6 damage halved on save). This is a fairly potent attack, but can be repetitive and weakened against certain character builds (or as the party learns how to neutralize poison).

Would there be any damage to balance (effecting CR) if that stinger was replaced with other damage types. I'm thinking of a wyvern that stings and does Shocking Grasp, or Fire Bolt, Ice Knife or other cantrip type effects within the sting. They'd do similar type of damage, but have a changed damage type.

If the damage amount doesn't change there shouldn't be any change in CR.

 

[Illithidbix]

Some resistances/immunities are a lot more common that others.

Dwarfs have poison resistance, Tieflings have fire resistance and Dragonborn depend up their flavour.

Thunder, Radiant and Force Resistance/Immunity is comparatively rare.
(TMK, only the Helmed Horror is immune to Force damage, although a few Class Abilities let you gain resistance to it)

It's not significant enough to change CR.
Although it might be nice to have a mix of monsters who bypass the players of monsters and some that the resistances work upon.

In 4E it seemed every monster had a variant that was on fire.

 

[jodyjohnson]

Yes, that would be a straight forward modification. You'd probably want to signal it some way. Rumors, observations from tracking, or survivor accounts would do.