I've created a swamp combat encounter where there are foes on swampy islands a foot or two above the surface of knee-deep brackish water. All the water will be treated as difficult terrain, making it difficult to travel quickly from island to island. There will be artillery goblins (or some other kind of creepy swamp hag allies) on the "islands."
I've dropped hints earlier that there is a connection between the swamp hag and a young "Storm" Dragon and I'm considering having either the young Blue Dragon or a Blue Wyrmling son show up to harry the party in the middle of the goblin combat. I'm further considering having any lightning breath weapons do additional damage to character caught standing in the water between the islands.
What do you think of this idea? have any of you done something similar? What kind of extra damage would you think would be reasonable? Maybe for simplicity sake giving them "Vulnerable 5 Lightning" when they're in water? Or maybe Lighting attacks roll 2x dice? e.g. 2d6+4 Lightning attacks become 4d6+4. Of course I'd need to extend this house rule to the players vs. foes and for the remainder of the campaign to be consistent...
I've dropped hints earlier that there is a connection between the swamp hag and a young "Storm" Dragon and I'm considering having either the young Blue Dragon or a Blue Wyrmling son show up to harry the party in the middle of the goblin combat. I'm further considering having any lightning breath weapons do additional damage to character caught standing in the water between the islands.
What do you think of this idea? have any of you done something similar? What kind of extra damage would you think would be reasonable? Maybe for simplicity sake giving them "Vulnerable 5 Lightning" when they're in water? Or maybe Lighting attacks roll 2x dice? e.g. 2d6+4 Lightning attacks become 4d6+4. Of course I'd need to extend this house rule to the players vs. foes and for the remainder of the campaign to be consistent...