D&D 5E My 20th Level Rogue wants to use Stroke of Luck to tame a demonically possessed red dragon...

[Sunseeker]

Used to be there were stages of "friendliness" that you had to get through in order to tame a creature.
Something like "unfriendly, neutral, friendly" etc...

First off, he's going to be attempting to reason with the demon, not the dragon. So Handle Animal is right out the window, and frankly I wouldn't let Handle Animal apply to a dragon in the first place. They're sentient, not animals. At best all he's going to achieve is to get the demon to move from unfriendly to neutral.

Frankly, your party would have a better chance at befriending the dragon simply by getting the demon out of his head.

 

[snickersnax]

The DMG has some rules for resolving these kinds of interactions on page 244 and 245.

Here is one I would probably apply in this situation:

That said, a hostile creature might be so illdisposed
toward the party that no Charisma check can
improve its attitude, in which case any attempt to sway it
through diplomacy fails automatically.

 

[BookBarbarian]

I think a dragon is not tame-able any more than I'm able to tame my boss or my wife. It is a sentient creature.

 

[Shasarak]

The dragon is an intelligent sentient creature. It isn't something that can be "tamed."

I am a bit more old school then this. If you do enough subdual damage to the Dragon you can tame it or at least it is intelligent enough to submit to you which is essentially the same.

 

[OB1]

A DM should only ask for an ability check if the results of the players declared action are uncertain to you.

If you as the DM deem that what the PC is attempting to do is impossible, then no check is required and Stroke of Luck doesn't come into play.

 

[Bigsta]

Ten years from now when one of your players is in a discussion about their favorite campaign, he/she isn't going to talk about the campaign the ended with them fighting yet another dragon, demon possessed or not.

The campaign they will look back on most fondly was the one in which the DM let the players get a "Fallout" ending. Not only should the players have the chance to tame the dragon, but they should also be able to convince the dragon to commit suicide rather than continuing its torment as a demon's puppet.

Adventuring. . . Adventuring never changes . . .