A question was asked on ENWorld: "What tactics do a supra- genius dragon use?"
Well, I'm not a supra-genius dragon, but I've been known to play one in D&D. Perhaps more to the point, nobody is a supra-genius dragon, which means that there are no 'right' answers anywhere... nor any 'wrong' answers either.
However, what we do have is "The Art of War", and other documents on the topic. However, "The Art of War" has two specific advantages:
- I've actually read it.
- It talks about tactics in general terms, rather than dealing with specific cases. This means that the lessons it contains are transferable, which is not always the case with other works.
So, anyway, what lessons does AoW have for our supra-genius dragon?
Lesson #1: Know Yourself
I always find it funny when film characters 'quote' from "The Art of War". Invariably, the quote runs something along the lines that the first rule of warfare is "know your enemy". It isn't - it's know yourself.
The key thing there is that our supra-genius dragon would start with a catalogue of its abilities, its weaknesses, the resources it can call on, and so forth. And, being a supra-genius, it would then take steps to maximise its strengths and minimise its weaknesses.
In 3e, this probably means making heavy use of its spellcasting abilities, either to develop protections against the opposed energy type (the one to which it is vulnerable), or to outright ward itself against magic, or similar. It would mean investing some of the resources in its hoard into useful magic items - a ring of wishes, or a wand of cone of cold for a red dragon, or what have you.
In terms of preparing the game, the DM should spend quite some time with the dragon's stat block. Work through every power and every resource that the dragon has, and consider: how can this ability be used to advantage? How can this weakness be countered? What can the dragon have done to expand its resources? And then do all of those things.
Lesson #2: Know Your Enemy
So, an unknown foe appears out of nowhere and starts attacking. What do you do?
Well, the key word there is 'unknown'. Since you don't know your enemy's capabilities, you can't assess the risk. So the answer is to refuse the engagement - the most likely tactic to use is retreat. Then wait a while, and inflict a devastating counter-attack.
But, of course, the supra-genius dragon should never actually let things get that far - it should be gathering information on any credible threat as soon as it appears on the radar, with a view to wiping it out long before any potential threat becomes an actual threat.
In terms of preparing the game, the DM should feel entirely justified in spending time with the PCs' character sheets. Look through every power they possess, every item they possess, and all the tactics that they have employed to date. The dragon would be aware of all of these (except, perhaps, the most recent additions). He would know that the party consists of a 15th level Wizard, a 15th level Druid, a 15th level Artificer, and so on... and would plan accordingly - even as far as knowing that their defensive magics will mostly last two and a half hours before expiring.
Lesson #3: Never, ever, Fight Fair
What, you think a dragon is just going to wait in it's lair for you to show up, then slug it out toe to toe while you gang up on it? Don't be silly.
"The Art of War" notes that the very best way to capture a city is to avoid fighting for it at all. Get the city to surrender, and you get all the glory with none of the risk. If you must fight, do so at a time and place of your choosing. And never, ever, give a sucker an even break.
What this means is that the dragon should seek to stack the deck as heavily against the PCs as it can. Find the weaknesses that the PCs have and exploit them, mercilessly. Deny the PCs any opportunity for respite. And, in D&D, go for overwhelming force rather than attrition, since the latter doesn't actually work - healing is just too easy.
So...
If Smaug were a true supra-genius (and a D&D dragon rather than a LotR one), then the people of Laketown wouldn't be at all willing to help the dwarves. On the contrary, the moment it became known that Thorin and his company were intent on slaying the dragon, they should have been bound and turned over to the dragon for tribute.
Why? Well, the dragon should have been in communication with Laketown (and any other settlement within a day's travel of its lair). The message is simple: Smaug will not ravage your town, and in fact will protect it, provided two things: 1) You provide annual tribute, and 2) you do not aid those who would oppose me. But, of course, if you do dare to oppose me, I'll wipe you out without mercy.
This has three advantages for the dragon: it gets to build its hoard. Mmm, gold. It gets to enjoy the fear that its presence engenders, and thus feed its pride. Mmm, pride. But, most of all, it negates many upcoming threats - those dragonslayers are now not just fighting the dragon; they're also fighting the town.
And, critically, that arrangement also benefits the town - with the dragon keeping down any other local predators, not to mention ravaging those villages that are just a little further out, the town can actually prosper. Bandits won't raid their shipments of good out of fear of the dragon, which means the gold rolls in. And, yes, the dragon takes a tribute... but if the town is booming, that actually matters less. It's actually likely that the town will not only oppose the dragonslayers out of fear, but because the dragon is good for the town!
In D&D 3e, the most dangerous PCs are very definitely spellcasters, with the Wizard and the Cleric being top of the heap. But both of these classes have one big weakness: they need to prepare spells. The Cleric, in particular, needs to do so at a particular time each day. And you can bet that, for convenience if nothing else, the Wizard will prepare his spells at the same time.
So, that's the time the dragon should attack. Or, rather, that's when he should have his allies attack. Not to kill, necessarily, but rather simply to prevent spell preparation. So, the Cleric has to break off his prayers... and loses the chance for the day.
The Wizard has to break off his preparations, but can come back to them later. Fair enough. He'll rush over to where he has a good vantage point, and start casting.
Great. Now steal his spellbooks.
Because what the PC Wizard will never do is take the time to carefully pack his spellbooks back up in his backpack or bag of holding. They'll be left sitting in his tent while he deals with the threat, safe for anyone to take them.
(And the reason you steal them rather than destroying them is simple: a trivial mending spell can repair a damaged book, but won't help if they're gone.)
Actually, while you're at it you might want to think about sundering holy symbols, destroying favourite weapons, and so forth. Basically, you want to degrade the ability of your foes to come after you... but don't bother inflicting injury because a simple heal spell will fix that.
Frankly, it's a shame D&D doesn't have rules concerning PCs' need to visit the bathroom, or else the dragon would be taking advantage of those.
Lesson #5: Deadly Ground
"The Art of War" has a lot to say about different types of terrain and how best to respond to them. The dragon has two key advantages over would-be dragonslayers: it gets to choose the terrain, and every type of dragon has at least one specific energy immunity.
So, the supra-genius dragon should be looking to use this advantage, just like all the others. Its lair should be an environment inherently hostile to those who would oppose the monster - a lava-filled volcano, an acid-filled swamp, or whatever. Smaug should have been quite happy when Theoden relit the forges of Erebor... he should have proceeded to start tipping large amounts of molten metal everywhere until the dwarves had nowhere to go and were being choked by the poisonous fumes.
Oh, and one other thing: the lair should have at least two exits. Retreat may be galling, but sometimes it is also necessary - it's not impossible that those would-be dragonslayers might just show up unexpectedly one day.
Lesson #6: Misdirection and Spies
Again, never give a sucker an even break. Illusions, false rumours, false lairs, lesser dragons in disguise, hidden pathways... Use them all. Have your agents attack from one side, while you sneak in at the other to hurt them. Or you attack from one side while your agents take care of business on the other. And then do it again, but differently.
Basically, if the PCs ever see a big, red, scaly monster breathing fire at them, and that really is the dragon, you've probably done something wrong.
Lesson #7: If All Else Fails...
Make arrangements for resurrection. Because you can bet the PCs will.