Knight vs Dragon

The classic trope of the lone knight against a dragon. Is it doable in D&D? I've never seen it happen. Seems like a suicide mission unless you're talking about a super, high level, overpowered character, but where's the fun in that?

Before writing this, I watched the dragon fight scene in the Disney classic, Sleeping Beauty (1959). It's really the only on-screen visual I could think of that matches this scenario.

• That dragon was black and breathed green fire which had acidic qualities.
• Wondering if this influenced Gary Gygax's version of a black dragon.
• The knight (or was he just a prince?) hit the dragon once on the nose and it sounded like metal.
• The knight (prince) lost his shield to the dragon's breath weapon (saving throw in action?)
• The knight slew the dragon by throwing his sword (which had just been enchanted by a faerie) into it's underbelly.

Time to roll up a fight... 

• B/X will be the system.
• The dragon will be a standard black (7HD).
• The knight will be a 7th level knight as offered by Old School Essentials Advanced Fantasy, though for all intents and purposes, it is essentially just a regular B/X fighter because none of the knight class features apply here at all, unless the dragon had spell casting capabilities, where-as the knight would be granted a saving throw vs sleep.
• The knight will have four randomly determined magic items including a magic sword, representing time spent adventuring. I rolled shockingly well for these, see below...
• Black dragons have a 20% chance to speak, and thus, cast spells. This dragon is a non-speaker, so, no spells. This alone, makes the dragon much less formidable.
• The breath-weapon will work on a recharge mechanic after the initial use. The rules state there is an equal chance of the dragon using claws/bite as there is of it using it's breath-weapon. Random determination will mean breathing acid on a 4-6 (d6). Maximum 3 times. 

The Knight

Str:15(+1)   Int:10   Wis:13(+1)   Dex:10   Con:12   Cha:11

HP:36    AC:17(plate + shield)   Dragon-Breath Save:10    To-Hit:+7    Damage:1d8+2

Magic Items:

• Sword+1 (+3 vs Undead)
• Ring of Wishes (1) (actually rolled this, could be a game changer)
• Potion of Healing 
• Boots of Traveling and Leaping (why did OSE rename the Boots of Striding and Springing?) By-the-book these won't help much here, but I might allow advantage on breath-weapon saves or some such thing.  

Black Dragon 

AC:17    HP:31    To-hit:+6    Damage: 2 claws (1d4+1), 1 bite(2d10), or 1 breath (current HP)    

Morale:8 (will check at 16 and 8 hit points)

Round One (assumes no surprise)

• Dragon wins initiative breathes acid.
• Knight makes the save and takes 1/2 damage, 16 points.
• Knight then hits dragon for 9 points.
• Knight HP:20   Dragon HP:22

Round Two

• Initiative is tied, combat will be simultaneous.
• Dragon breathes acid again.
• Knight fails save and dies while striking the dragon for 6 points of damage.
• Knight HP:0   Dragon HP:16

That was quick! 

Lets go again with the following caveats: 1. The boots of traveling and leaping will allow the knight to take zero damage if the save vs dragon-breath is made and half damage if it fails. 2. The knight may also sacrifice a shield to avoid breath-weapon damage on a failed save or a killing melee blow.

Round One

• Dragon wins initiative breathes acid.
• Knight makes save, using the boots, leaps out of the way taking zero damage then hits the dragon for 6 points of damage.
• Knight HP:36   Dragon HP:25

Round Two

• Dragon wins initiative and chooses 2 claw/1 bite... all three miss!
• At this point the knight could use the ring of wishes any number of ways to win the fight, it's such a game changer that I passed on that for the sake of this exercise. So the knight strikes and hits again for 6 points of damage.
• The dragon passes a morale check, continues the fight.
• Knight HP:36   Dragon HP:16

Round Three

• Initiative is tied, combat will be simultaneous.
• Dragon breathes acid, knight makes save, jumping away taking zero damage. While jumping, strikes the dragon for 10 points of damage!
• Knight HP:36   Dragon HP:6

Round Four

• Knight wins initiative and hits the dragon for 8 points of damage, slaying it.
• Knight HP:36   Dragon HP:0

Thoughts...

• Simultaneous combat has interesting consequences.
• In either fight, the knight never missed an attack roll, had to roll 10+.
• House ruling the magic boots gave the knight a nice edge, seriously helped by making both saves. This makes sense though, and is probably how these boots would work in sword & sorcery fiction.
• The knight took zero damage in the four round second fight mainly due to the dragon rolling very poorly.
• I initially rolled morale at the end of the third round. The dragon failed and flew away (realistic.) Then I remembered that initiative had to be rolled first, which the knight won, then proceeded to slay the beast. Rolling initiative every round has dynamic effects.
• The ring of wishes could have been used to nullify the dragon-breath, blind the dragon, put it to sleep, etc. Not the best item for this exercise, that's why I didn't use it.
• Great little fight, easy to visualize, quick and dramatic not unlike the scene in Sleeping Beauty.

I think the knight's chances of success in this scenario diminish further and further with every edition following B/X & AD&D due to the fact that dragons keep getting bigger and bigger, though I'm not about to put that to the test.

XP & Treasure

• Slaying the dragon: 1,250 XP
• 58,000 SP (GP value: 5,800)
• 20 gems (GP value: 2,610)
• 40 pieces of jewelry (GP value: 48,000)
• Total GP value: 56,410. Slightly under the average of 60,000 for a black dragon.
• Total XP: 57,660. 

Enough for this knight to ascend to 8th level!