Counter-example:
The next time the PCs show up, the dragon is waiting in ambush along with whatever forces it has remaining and crushes the unprepared PCs who didn't think they would encounter the dragon until later.
so either A) the PCs die and the game ends... or B) PCs just fall back again and rinse repeat the hit and run tactics just with more care?
how does either solve any issue?
OR
The dragon goes hunting the PCs and attacks when they are resting, breathing on their entire camp before they can do anything. Since they are sleeping, the automatically fail DEX saves and take full damage.
actually I am pretty sure I even had one of my exmaples include this scenero... I don't see how it changes anything I said.
Allowing PCs do repeatedly do hit-and-run tactics is pretty bad on the opponent's part. Once, maybe twice, sure, but after that the PCs should become the hunted, not the hunters.
and when they hunt... they hunt and the PCs still win, taking down a portion of there forces.
if the enemy has 500 soldiers, and can replenish 10 soldiers per day... if every day (weather it be PC hunting them or PCs laying traps for when they hunt PCs) the PCs kill 25 of the solders then the soldier number drops by 15 per day... after 10 days they are down by 150, after 10 more (20 total) they are down 300... aka more then half. after 10 more days (30 total) they are down 450 and that 500 army is a joke now at 50.
this works as long as the PCs are winning (and by winning I just mean killing more then can be replaced and getting away alive)
Counter-example:
After repeatedly being hit by the PCs the orcs trail the PCs to where they are resting, and sack that city--including the PCs.
and again as before... the PCs win (with win be kill more then can be replaced) or die... and how does that change this at all?
Again, allowing hit-and-run tactics over and over just sets up the players to think it should always work--when it is poor tactics to allow it to IME.
but so far your answer to stop it has been "Have the next bad guy fight come to them so they don't waste time/resources on getting to the next fight..." I don't understand the angle here.
the tactic is space out fights... so if on day 3 you have the bad guys start a fight at the PCs, then day 3 5mwd is just one the PC didn't have to travel for.
Again, hit-and-run and allowing the players to pick the battlefield?
becuse I'm not sure you understand that the players are TRYING to pick the battlefield... if they are doing it well (and for this we assume they are if they do so poorly that handles itself) what do you do then?
I would hope 7 high-level Wizards (INT was their highest scores, right?) would be smarter than that.
it was 3.5 so some might have been blond air heads (aka high cha low int sorcerers) I don't remember... but we still ran circles around them... and when they DID show up or try to one up us it was just us improvising that day and adapting so that trick would not work again.
Why would they never gang up against you?
cause we didn't let them... we kept pulling them apart.
I could see maybe a progression like you take out 1, then a second, and now the remaining have a couple gang up against you, and if you defeat those 2, the last 3 form treaty to destroy the PCs as a united front.
if I remember they didn't even know who we were when we killed the 1st one... and by the 3rd they made the mistake of trying to trap us but we saw it coming and turned the trap killing all the undead one had... we then also had a time that when they came after us we just plane shifted around until the ran out of plane shifts... and we had allies set up to smack there PMP allies.
Frankly, this smacks too much of the DM allowing the players to steamroll over monsters and not having the monsters react. How would the PCs react if they were the targets instead?
I mean if you mean it is a story we won... yes we won. that is why I am telling it. If the antagonists had tried to do it to us either A) the campaign ends with us all dieing (and most likely just is not fun) or B) they failed and we won anyway...
I'm still not seeing how you have an aswer that isn't "Well I would just throw infinite dragons and TPK"
I'm sure there is a lot more to these scenarios, but from what you have said I can think of a lot of ways of stopping PCs from being able to get in the rests required to keep allowing such tactics to work.
okay and what does that accomplish?
Having said that, I want to emphasize that stopping rests only works (for ME) if the narrative of the story also supports it. If it doesn't then something else will happen. Take the hunting the dragon example. If the PCs destroy the dragon's minions, and the dragon has nothing left to help it take on the PCs, I would certainly consider just having the dragon flee (with his treasure

).
yup... so then the Dragon is on the run being chased by the PCs who already took out his forces and now he doesn't even have his lair as a resource...
Another option is (depending on the dragon type) having the dragon trail the PCs to their base camp, wait for them to leave, and then burrow beneath it, creating a pitfall, and waiting in ambush for their return...
and then you fight the dragon 1 on 1 (well 1 on 4 or 5 really) and the PCs win or lose, if they lose the campaign ends and if they win all you did was reward the tactic anyway...
I mean heck if after 1 day of hit and run on it's forces you had the Dragon leave it's lair and come at the PCs that seems like it was a TRUE perfect win for the PCs... they wanted the Dragon alone in a more vulnerable situation.
yeah but what ones stop the 5mwd?