I've learned the hard way that a Dragon that is 2/3rds damaged is a Dragon that should be running away to fight another day.
Several of the PCs in my campaign have some way to do major damage at least a few times per day. So, the instant a dragon appears, they start shooting with the big guns.
The trick is to move in, focus attacks on one PC, and then fly away.
In our campaign, we have a reoccurring villain green juvenile dragon that does precisely that. It has fought the PCs 3 times now, killing one PC the first time.
However, the PCs, as they go up in levels, are getting more powerful, so the last two fights were not as impressive. In fact, in the last fight, the dragon flew away whining "It's not fair" (course, when the PC Wizard used Benign Transposition to switch the PC Monk that the Dragon almost had dead with the fresh PC Paladin, it was like starting the combat all over
Boy, did that tick off the dragon). One down side of dragons is that as reoccurring villains, the PCs tend to get a lot more powerful whereas the Dragon tends to only improve slightly (maybe a few upgrades to his lair and tactics somewhat).
On the bright side, the reoccurring villain Wizard (who has fought the PCs 4 times) took note of the last battle with the dragon, so he offered a partnership with the dragon. The dragon accepted. So, they are preparing an ambush (that is, once the Wizard finishes with his current scheme which for certain reasons, does not include the dragon). Both the Dragon and the Wizard plan to use the other to both do and absorb most of the damage to/from the party and then plan to wipe out the other once the party is destroyed (but only if the party is destroyed, the alliance is too valuable for both sides to break until then).
And since the Wizard has a very high intelligence, he will plan the entire attack, giving the Dragon tactics that it has not thought of previously (his Int is 5 higher than the dragon's).
But, I can understand the OPs POV. Parties tend to have a lot of options and they get more actions per round than a Dragon. If a Dragon does not start wiping them out quickly, it is often in serious trouble. And, even the best tactics by a dragon can sometimes be underwhelming at best (e.g. I have seen a dragon breath weapon rolling low and doing 2/3rds or less average damage, everybody saves, and it hardly slowed the party down).
Several of the PCs in my campaign have some way to do major damage at least a few times per day. So, the instant a dragon appears, they start shooting with the big guns.
The trick is to move in, focus attacks on one PC, and then fly away.
In our campaign, we have a reoccurring villain green juvenile dragon that does precisely that. It has fought the PCs 3 times now, killing one PC the first time.
However, the PCs, as they go up in levels, are getting more powerful, so the last two fights were not as impressive. In fact, in the last fight, the dragon flew away whining "It's not fair" (course, when the PC Wizard used Benign Transposition to switch the PC Monk that the Dragon almost had dead with the fresh PC Paladin, it was like starting the combat all over

On the bright side, the reoccurring villain Wizard (who has fought the PCs 4 times) took note of the last battle with the dragon, so he offered a partnership with the dragon. The dragon accepted. So, they are preparing an ambush (that is, once the Wizard finishes with his current scheme which for certain reasons, does not include the dragon). Both the Dragon and the Wizard plan to use the other to both do and absorb most of the damage to/from the party and then plan to wipe out the other once the party is destroyed (but only if the party is destroyed, the alliance is too valuable for both sides to break until then).
And since the Wizard has a very high intelligence, he will plan the entire attack, giving the Dragon tactics that it has not thought of previously (his Int is 5 higher than the dragon's).
But, I can understand the OPs POV. Parties tend to have a lot of options and they get more actions per round than a Dragon. If a Dragon does not start wiping them out quickly, it is often in serious trouble. And, even the best tactics by a dragon can sometimes be underwhelming at best (e.g. I have seen a dragon breath weapon rolling low and doing 2/3rds or less average damage, everybody saves, and it hardly slowed the party down).