How to make sure players know they should run

[Telok]

1. Use a system that isn't focused on physical combat to the point where significant numbers of characters can only do things outside of that with high rolls of the dice.

2. Use a system that directly and mechanically rewards stuff other than combat.

3. Use a system that doesn't have max speeds the characters can't exceed, monsters faster than the characters. A system where doing anything useful to slow down the monsters requires both moving less and rolling high on the dice punishes the players for trying to flee.

4. Use a system that isn't locked into battle mat based, arena style movement and positioning. Battle mats cause you to treat the edges of the map like impassable walls.

[Kurald Galain]

If running isn't viable because of movement rate, give the party a bunch of potions of Invisibility; that's a pretty good escape card. At higher levels, suggest that the casters carry a scroll of Dimdoor / Teleport / Word of Recall.

Alternatively, suggest that the PCs use bluff or diplomacy to make the bad guy spare them. Not all bad guys want everybody dead; perhaps they just want money, or information, or to imprison you and gloat, or whatnot. If one PC escapes and the rest are imprisoned, that makes for a solid escape/rescue scenario right there.

[Zakhara]

1.) Does you party know not every battle is meant to be doable?
2.) Does your party know the relative strength of their adversary?
3.) Does your party know there are alternatives to combat (if they exist)?
4.) Does the party have a real chance of dying here?

If "no" to any of these, you're putting yourself in a hard place. It's very hard to train a sense of risk-aversion overnight.

Normally I would advise letting them get in over their heads and die. But by the sounds of it, you need a very specific set of events to occur, one of which is their assured survival. That's hard to do without transparently stacking the deck against them and damaging suspension of disbelief (and player agency, to a degree).

My advice would be to make the party a secondary target. I feel like an enemy strong enough to win yet stops short is a near-impossible sell. Whereas if the party is there, as collateral damage, they can bear witness to the threat without raising the question of the enemy not finishing their plate.

[Kane0]

More information please! What system are you playing, how long have these people been playing (in general and this game), has this happened before, etc

Edit: Oh and yes, often I will simply say "You don't think you could take this in a fight" as soon as a suitably powerful creature demonstrates said power. Assessing threats is part of the job for an adventurer.

[MoiMagnus]

I don't think it's your responsibility to do that.

It is.

Or at least, it might. The main reason why I've seen player not run away is because they deeply trust the DM not to put an impossible fight.
The last thing you want as a DM is to break trust, so it is your responsibility to make sure they understand they should not take winnable fight as granted BEFORE punishing them for doing so. Otherwise, that's betraying trust, and the players will consider you as a jerk rather than thinking "we should have run away".

Then, once you've made clear you do not guaranty every fight to be winnable, which a lot of DM make at session 0, it is indeed no longer your responsibility.
(Well, since you should try to have a DMing style that please both you and your players, checking if your DMing style is adequate to your group is a continuous responsibility, but that's another subject)

[Lord of Shadows]

Now I ask how do you tell your players that basically "this guy is way to powerful for you, you shouldn't keep fighting him." The enemy just being more powerful than them isn't working so I'd like extra ideas.

It's a little late now, but perhaps in the lead-up to encountering the powerful baddie, the party kept hearing how impossible he was to defeat. And hearing this more than once, and in the context of more powerful parties encountering him. This, along with an occasional story of a harrowing escape, seemingly allowed by the bad guy only to increase his reputation as "impossible to defeat."

We started at 1st level ... and we were hired to explore an abandoned mansion by a city official who lied to us about his interest in the mansion.

While exploring the mansion, we discovered a bunch of interesting things about the mansion and about its prior owner. We discovered that the last owner was a mad alchemist who made a bunch of low level flesh golems (broken ones), many of whom were still in the mansion and we found out that he killed his own daughter to remake her as a broken one. Her ghost/spirit was still haunting the place. We eventually figured out that the city official -was- the mad alchemist responsible for all of this. And he wanted us to destroy a special seal that was what kept him from retaking his mansion. And the only way to let the ghost rest was for him to face his punishment at the hand of his creations.

So, we dutifully lured him back to the mansion, thinking we'd be able to... you know... actually succeed at the apparent goal given to us.

Once we got him back and he fell into our "trap" we found out he was a 20th level lich who promptly killed us all, took out the broken ones and cleared the map. Oh yeah? that "seal" had no apparent effect on him at all after we'd gone to the effort to try and fool him into thinking it was gone and thought it would do what it was stated to do.

Then raised us up and gloated and sent us on our way.

This would have been soooo epic if it had actually worked. Or, even better, if it had seemed to fail, and then suddenly worked somehow. Outsmarting the BBEG at his own game is priceless. In another universe, for example, some powerful good creature was watching this unfold, and stepped in at the end using the seal to defeat the Lich, succeeding only because your party brought him to it. Unfortunately, your DM did not run it that way...

[King of Nowhere]

It's important to also consider why the party is fighting insurmontable odds. If the DM throws strong enemies one after the other for no reason beyond proving a point, the players will feel betrayed.

In my campaign i established crafty, resourceful enemies, and they manage to get the drop on the party every once in a while. I remember two instances where the party had an ambush turned on them because they enlisted the help of npcs who secretly had an interest in seeing them fail.
Even though i cpuld not reveal it straight away, when the party ambushed their foe and in that very round a couple dozen high level foes teleported to join the fray, the party understands they have been outsmarted somehow. They realize the current plan has failed and they may be forced to escape.
Which also makes for a good story. Especially when, after the mysteries are discovered, i can reveal what actually went on.
And it feels better winning after the enemy gives you real troubles. It makes for a strong villain, which is more satisfying to eventually defeat. If the boss is a pushover, it feels unsatisfying.
The players know that if they have a good plan, i give them a good shot at it. My enemies are crafty and prepared, but within reasonable limits. If their plan has flaws, or if they let it leak to the wrong people, the enemies may be able to exploit it. And then it's still a toss up. Damn hard to predict the exact difficulty of a fight at high level.

So, maybw you could ensure that they know why they are being outpowered when it happens.

[Lord of Shadows]

And it feels better winning after the enemy gives you real troubles. It makes for a strong villain, which is more satisfying to eventually defeat. If the boss is a pushover, it feels unsatisfying.

This is good advice..

So, maybe you could ensure that they know why they are being outpowered when it happens.

One way of doing this is to use the party's encounter with the powerful enemy to introduce an equally powerful foe of the enemy who pops in unexpectedly and attacks, using the party as a sort of diversion. Also a DM sort of way to "save" the party. The BBEG could be driven off, and the party could possibly gain some valuable intel from this new "enemy of their enemy," intel that could help them realize this foe is way over their ability to handle. Because, of course, the friendly help was just by chance this time and will not always happen. This enemy of their enemy could be anyone - even someone the party thought was their enemy (and maybe really is... the "onions have many layers" theory).

[Resileaf]

I think players think they need to fight because if they try to run, they'll just die. After all, if this enemy is strong enough to beat then, why would he not be fast enough to catch up to them (or even worse, if the enemy isn't actually fast enough to catch up to them, your players are definitely going to want to use ranged tactics to whittle him down)? Or if you expect your players to surrender, they might not believe that they are likely to survive being this person's prisonners.

Damage indicators are not enough, you have to also make it clear that they can leave the battle without dying. Otherwise, players will take the option to go out in a blaze of glory any time.

[LibraryOgre]

Easiest? Casual murder of an NPC that the players know the stats of. If BBEG casually kills Mirt, the 3rd level fighter, they know that he can do significant damage.

[Psyren]

I don't think it's your responsibility to do that.

This. Just kill them.

Note that this doesn't actually mean you have to KILL them.

You can have them "black out" and then wake up somewhere, missing some or all of their equipment and on the verge of death. In the BBEG's dungeons for example, or outside the cave they were in, or at the creepy old witch's nearby hut, or at the Plucky Freedom Fighter's HQ. Just because they hit -10 or whatever in combat doesn't mean you have to immediately make them reroll, but it might be enough to teach them some caution. Your job as GM is to give them a sense of danger/trepidation, the choice to follow through on that all the way is up to you.

[Psikerlord]

recently I've run a few encounters for players that were all basically meant to be ones that were put there to make them realise how strong/powerful the enemy they're facing is and then run away...it's the running away part I'm having trouble with.

My players keep fighting, even if I say the attacks barely do anything and the damage they take is very high. Even when it's in a do or die situation instead of running they just keep fighting no matter what. It's not character ideals or anything, a lot of characters who are tactical geniuses or run when they're in a bad situation just keep fighting.

Now I ask how do you tell your players that basically "this guy is way to powerful for you, you shouldn't keep fighting him." The enemy just being more powerful than them isn't working so I'd like extra ideas.

I think the best thing is to introduce a formal "Party Retreat" rule (with a cost) and emphasize this rule exists. Then next time, if they dont flee when they probably should, just keep the dice rolling in the open until they either miraculously win or it's a TPK. Next campaign they'll start retreating. Short term pain but long term gain.

[Kane0]

In the case of 5e, remember the Chase rules exist.

[KineticDiplomat]

Don't play D&D.

Really. The mechanics, theme, and player-culture of D&D are centered on killing increasingly challenging creatures as PCs increasingly grow in power. The non-combat rules, especially any non-dungeoning one, are...well, lets just say they are clearly secondary efforts. The story starts small, characters start small, and eventually they grow big by killing. You kill your way up the chain of awesome, and in doing so expose increasing epic-in-scale plot points or adventures while you progress from bit mercenary/charlatan/whatever to demigod.

I mean, you don't have to run a table like that, but it's pretty much what you think when you hear "D&D." Which means the basic assumption is that the game is a medium to bounce from encounter to encounter, slowly getting better at killing things, and that they will be handed an appropriate mathematically solvable outcome. So when players play D&D, they act like the thought is that every fight is there to be won unless there are BIG, DRAMATIC, WARNING SIGNS. And even those may just be interpreted as "oh, that's a boss fight. We should make sure we bring enough spells."

So, if you want players to not act like suicidal glory hounds, ****-sure in their near immortality, don't play D&D.

If the story you want to tell is one of clever weighing of the odds, tactical maneuvering, and choice use of violence towards certain ends, don't play D&D.

If you want treason, intrigue, and political cunning to create no-win fights, don't play D&D.

If you want the fights to revolve around player skill at managing the fight and not their character optimization, don't play D&D.

If, and only if, you want to play some version of Boy becomes Boy-Of-Destiny through appropriately resolvable eno****ers, should you first look to D&D. For any other story, any other playstyle, there is a way better system somewhere.

[Kane0]

@KineticDiplomat Is that a Combat-As-Sport thing or a D&D-the-gateway-RPG thing?

[King of Nowhere]

Don't play D&D.

Really. The mechanics, theme, and player-culture of D&D are centered on killing increasingly challenging creatures as PCs increasingly grow in power.

So, if you want players to not act like suicidal glory hounds, ****-sure in their near immortality, don't play D&D.

that's way too extreme. i've never seen a player with such expectations. those that do have those expectations will still recognize when a fight is going downhill. even if they are sure of their immortality, as soon as they die once they realize this is a table where it can happen.

i don't know what kind of morons lurk out there, that people can consider them as normal

[Pleh]

I think this is mostly a question of managing expectations. If the players decide to flee because they expect it to be the most viable option, maybe it's better to switch to Chase Rules than use the combat rules to punish them just because it's most optimal for the NPCs.

Likewise, if you mean for them to retreat and they don't see a justification, or they suspect that combat rules make that choice untenable, no need to railroad them into running away. That's when the, "kill them" advice comes into play. They dug their heels in on a fight that they couldn't handle.

The main thing to me is to make sure you're not getting adversarial about it. If you're killing them, it's just because they stick it oit when they should have fallen back. If they're rabbitting, they've already accepted a loss, there's no reason to kick them while they're down unless they actually fall into an ambush. Sure, most monsters could easily outrun the heroes, but it's not guaranteed that they would try. Monsters aren't always fighting because they're hungry. Sometimes they're just territorial and won't pursue the threat far past their jurisdiction (and they might be less interested in forcing the heroes to stop running and more interested in making sure the heroes will think twice about coming back again).

[Tanarii]

Sure, most monsters could easily outrun the heroes, but it's not guaranteed that they would try. Monsters aren't always fighting because they're hungry. Sometimes they're just territorial and won't pursue the threat far past their jurisdiction (and they might be less interested in forcing the heroes to stop running and more interested in making sure the heroes will think twice about coming back again).

Besides, as players often learn, blindly pursuing enemies to try and run them down and kill them often leads you into a situation that gets you killed.

Depending on the game situation, player char ayers often have it worst in that regard, since they often don't have allies nearby and are in the enemy habitat. But even then it's often possible
to lead the enemy towards another threat.

If the enemy is more powerful than you, faster and has more endurance than you, has no danger from pursuing you, and has motivation to pursue you ... likely you should have looked before you leaped into combat. In spite of direct DM warnings that their campaign will be like that, many players need to learn that lesson the hard way.

[Pleh]

In spite of direct DM warnings that their campaign will be like that, many players need to learn that lesson the hard way.

Hm. I agree up to a point. Players that treat it like a game and aren't seriously invested in the outcome can take what they have coming to them. They'll either snap out of it, or settle into a light hearted, beer and pretzel playstyle where they just expect to routinely roll out new characters and no lesson really gets learned (and that's just a valid way to play). For players who are already invested and are sincerely doing their best, I'd avoid letting the system throw its full weight to bear on them. That's where I'd use Psyren's advice about "death lite" where instead of actual death, they wake up in prison (or similar, etc).

If they're not invested, let the chips fall. If they really care and just made a tactical blunder, remember that failure doesn't have to mean rolling a new character and starting over.

[Zakhara]

Don't play D&D.

For this thread, I would amend this to "don't play D&D 3e and on." The old-school game is perfectly adept at teaching short, sharp lessons. But even that's beside the point, as OP isn't asking for a different game.

[Pauly]

Some things. RPGs generally, and D&D in particular make the mechanics of running away very difficult.

In reality running away is much more viable than portrayed in D&D, and much easier to achieve.

So if you want to home brew some “free” mechanics first. Then the players should see that it is a viable course.
What I would suggest (I haven’t played D&D for a long time so the mechanics may have changed)

Declaring “flee”.
1) The character triggers no Attack of Opportunity for moving from adjacent squares from an opponent.
2) the character moves at double rate.
3) after declaring that he/she is fleeing the character must continue fleeing until they exit the map/combat area. Each turn they must move towards their nearest safe exit.
4) a fleeing character may not attack or cast offensive/damaging spells. A fleeing character may, at the DM’s discretion may cast defensive skills that will delay pursuit such as grease or web.
5) the fleeing character is more difficult to hit and there is a -5 modifier applied to any attempts to hit a fleeing character.

Having a home brew like this makes fleeing a mechanically sound and sensible thing to do. And if the party overmatches opponents who then successfully flee it shows them that they can do it too.

[Psyren]

For this thread, I would amend this to "don't play D&D 3e and on." The old-school game is perfectly adept at teaching short, sharp lessons. But even that's beside the point, as OP isn't asking for a different game.

That's because old-school D&D was a lot less focused on building character concepts. You could show up at a table with 5-10 character sheets and expect to burn through them all due to arbitrary deaths simply because making them took a lot less time, most of them probably had bad stats anyway, and you had no incentive to be particularly attached to any of them.

But fear of death doesn't have to mean threatening rerolls either.

[LibraryOgre]

That's because old-school D&D was a lot less focused on building character concepts. You could show up at a table with 5-10 character sheets and expect to burn through them all due to arbitrary deaths simply because making them took a lot less time, most of them probably had bad stats anyway, and you had no incentive to be particularly attached to any of them.

But fear of death doesn't have to mean threatening rerolls either.

I'd also say that it's because, in AD&D, there wasn't really such a thing as a "build"... who you were at XP 0 almost always defined what you'd be like at XP 1,000,000 (the two exceptions being 1e bards and human dual-class... though I've never heard of someone accidentally dual-classing; it's almost always planned from the start). If you start as a fighter/mage, you'll remain a fighter/mage, outside of weird circumstances (or reincarnation).

This changed with PO: S&P and S&M, of course, where you could build all sorts of things on the framework, and build in interesting ways... but that was an Option, and it was not, IME, well-embraced by the community as a standard assumption.

[Pex]

So what's the solution if level 1 players want to take on a lich?

Do you scale down the lich? If so, what do you do with all of the other level 1 threats (like wolves or bandits)?

I do agree that the DM should rarely throw those enemies at the players, as it really only leaves the players one optimal solution. However, that's not always realistic, and sometimes it can even be a good narrative tool.

Take, for example, the Curse of Strahd module for 5th edition DnD. It's probably the most popular module in the most popular edition of the most popular TTRPG in the world right now. And yet, the entire module is about trying to stop an enemy that shows up randomly throughout the campaign to torture and antagonize you. You know you cannot stop him, and he loves to remind you of that. On top of that, there is a fog that kills you, and prevents you from ever leaving the demiplane. Railroading can be done right, but there are definitely bad examples of it (Looking at you, Hoard of the Dragon Queen).

So can it be done? Yes. Should it be done? Maybe, but only if it's implemented well.

It's a matter of perspective and experience. When a 1st level party meats a lich it's not supposed to be a combat encounter. The lich wants to talk. There is no TPK threat. Only inexperienced and/or stupid players attack. When 15th level characters meet a lich, the answer is not so clear. Circumstances matter. It might be just an introduction to the true BBEG of the campaign. The party will fight him, just not yet. Maybe it is supposed to be the BBEG fight.

However, when the 5th level party enters a village and are told not to go through the mountain pass because no one ever returns from there, it's not the players' fault when they take that as a plot hook to investigate the mountain pass only to be TPKed by a beholder.

[King of Nowhere]

there's actually plenty of ways to escape. at low levels, fog and invisibility, grease and web. once you have access to teleportation, escaping is trivial. If the party doesn't have any of those, not even a scroll saved for an emergency, then it's really their fault. Can't say "but the system does not support escaping", because it does.

Even in the worst scenario, where there is no escape magic and the monster is faster than anyone, you can have everyone run in a different direction; instead of a tpk, one single character will die. And then you can resurrect him for 5000 gp, which is available even to low level parties.

[LibraryOgre]

"Some men... you just can't reach. Which is why we get what we got last week. Which is the way [they] want it. Well, [they] get it. Now, I don't like this any more than you do."

[KineticDiplomat]

Regarding the not-playing of D&D and people's responses:

It is true that the author did not ask for another system, yet none the less it may be his best answer. Here's why. If you look at the most common GM questions, you are going to find a substantial number that sound like one of the below.

"Why won't my players run away? I mean, this is clearly absurd for them, what do I need to do to not TPK them?"

"Why are my players all murderhobos? Can I stop them from being murderhobos? How?"

"Why are my players only interested in what the next encounter is, and are busily ignoring my world/plot/characters/factions/politics/setting/etc.?"

To which we get two basic responses; "Bash their faces in, that'll teach'em" and "well, what makes you think your players want to play that kind of game? Huh? Are you a <<Drumrolllllllll>> BAD AND RAILROADING/FICTION-WRITING DM?!"

Neither of which is an all that fair solution. The players, because they are playing D&D, are both mechanically and culturally inclined to believe that the game is mostly a series of winnable encounters, strung together by a plot. Unless they go off plot, in which case, they still expect to find a series of winnable encounters. The encounters are the meat of it. If they get their faces bashed in, particularly for no apparent reason other than wandering into the wrong alley so to speak, they are shocked - this is not how the world works! There may be dedicated roleplayers, smooth talkers, and problem solvers but the lowest common denominator of a D&D game is that there are going to be a series of party fights that you are expected to win to make the plot go forward, which in turn makes more winnable party fights. When that doesn't happen, cue discord. And if that is what the players want/expect with all their soul, well, it would be foolish to force something else on them.

But, the GM is also a player. He wants to have his fun, and presumably pours a lot of time and effort into the game. Oddly enough, he wants to do more than craft level-appropriate encounters for the PCs to kill tonight. He wants a game with a cool setting which influences the very nature of the game, or political infighting, or just "sensible adventuring." If he can't get any of the things he wants because his players are busy being suicidal murder-hobos who ignore everything else and never run, his fun stops. I's not the world he wants to be a part of, its not the game he wants to run. But he clearly wants to Play a Game and not Write a Book, because here he is asking how to be a better GM and solve those problems. So that he isn't writing a blog post. If his desires to run something other than continuous face-punching and the player's desires to continuously facepunch are not reconciled, eventually the GM quits and the game dies. He, after all, is not obligated to be a joyless encounter running sweatshop worker.

Now, there a loads of systems where at least part of what the GM wants is present. They not only thematically reinforce these ideas, but mechanically help keep everyone happy. They are systems where, if you want a low magic world, you don't have to make grudging concessions to the one guy who really wants to be a cleric and then you see everyone else get involved in a magic arms race - because if you can't punch faces hard enough, you're a bit crap in a D&D setting - and all of a sudden the entire setting, the reason the GM was interested to begin with, has been reduced to the same old string of D&D encounters. There are settings where if the High Threat Response Team shows up to your heist, the mechanical implication is that it is now very much time to GTFO, not see if this is a small boss fight. There are systems that are good at swordfighting, at pirating, at running an empire or having a debate, that are good at handling the supernatural, or encouraging roleplay, at virtually anything beyond the "string of D&D encounters you're expected to win." They just aren't D&D.

And in those systems the players can still be powerful, and interesting, and solve problems, and have cool dude moments, and feel good about themselves, and contribute to the plot, and all of the other things. They are just mechanically and thematically discouraged form being endless repetions of unthinking murder-hobos.

So we have a few options:


1) Try to incorporate things D&D is not, and is in fact mechanically discouraged from being, into D&D campaigns. And, often as not, failing at it because of the mechanical disconnect.

2) Run a campaign in a non D&D system, one which perhaps better reflects what ALL of the group - including the GM, who is not emotionless slave labor - wants.

3) Realize that there is no compromise, the palyers want to be unthinking murder-hobos and the GM wants a different style of game. Much like breaking a relationship,I would say it is better to pull the trigger cleanly than let it devolve into misery for the sake of having one.

[Tanarii]

If they're not invested, let the chips fall. If they really care and just made a tactical blunder, remember that failure doesn't have to mean rolling a new character and starting over.

Agreed. You don't change the way you run a series of adventure arcs (commonly misnamed a campaign) for a specific party that is in the middle of it. It needs to be explicit when characters are made.

It's too late for the OP. He needs to wait for the inevitable reroll and change up her style then, not try to force a change because plot points "require" it.

[King of Nowhere]

Regarding the not-playing of D&D and people's responses:

It is true that the author did not ask for another system, yet none the less it may be his best answer. Here's why. If you look at the most common GM questions, you are going to find a substantial number that sound like one of the below.

"Why won't my players run away? I mean, this is clearly absurd for them, what do I need to do to not TPK them?"

"Why are my players all murderhobos? Can I stop them from being murderhobos? How?"

"Why are my players only interested in what the next encounter is, and are busily ignoring my world/plot/characters/factions/politics/setting/etc.?"

those are common gm questions, but at the same time the fact that they are posted often does not mean that those problems are common. Only that they are more common than others. that's because people without problems don't post. I'm sure there's a specific kind of bias with a name for it, but can't find it.
In my experience, new players are unlikely to have those issues; being new, they come with no special expectations.
Old players have been at many different tables, so they know expectations can vary a lot, so they are receptive and do not have those issues.

What remains are not-completely-new players who only had experience at one or two tables, and may carry lots of expectations because they think everyone does it that way.
And toxic players, who are too dumb or too selfish to adapt to any table.

Not-completely-new players can be guided, most of the times. the first step is realizing the expectations they carry from the previous table are not necessarily true here.
Toxic players will be toxic no matter what. If they are young and new, there's a chance they may learn, or they may grow up and mature by themselves; otherwise, it's just better to stop inviting them.

I may also add players who are only interested in a specific kind of gaming. those are not toxic, but still it's better to not have them if you want to run a different game.

Now, regarding other system, there are certainly a lot of those, but only a few players can know them. If every DM uses a different system because it fits something he wants, then virtually every new player at a table will have to learn a system from scratch. that's too big a barrier for entrance, imo. And different systems also have plenty of issues. We know the issues of D&D better just because we are more practiced at it. And in all those systems, murderhobos will still go murderhobo unless the DM discourages them.

On the other hand, a great advantage of D&D is that it can be modded. You can vastly change the kind of stories and settings and powers you have, just by removing some content and adding a few houserules. And it is vastly easier for a new player to learn "we are playing a world where arcane magic is only innate, there are no wizards, no arcane scrolls, only sorcerors" than it is to learn a new system. It is also easier for the player to judge if he's going to like the new system or not.

ultimately, perhaps the strongest argument is this: if the players are expecting to never have to flee, the problem is player expectations. Thus this problem must be fixed by acting on player expectations. Changing the system will not change player expectations.
And maybe the new system will have great rules for escaping combat, but it won't matter if the players don't know them because they are in a new system with which they are not familiar. On the other hand, if those rules are that good, you may just want to adapt them to D&D.

[Mechalich]

ultimately, perhaps the strongest argument is this: if the players are expecting to never have to flee, the problem is player expectations. Thus this problem must be fixed by acting on player expectations. Changing the system will not change player expectations.
And maybe the new system will have great rules for escaping combat, but it won't matter if the players don't know them because they are in a new system with which they are not familiar. On the other hand, if those rules are that good, you may just want to adapt them to D&D.

I do want to say that the expectation by players that running away is rarely a good idea is, actually, players being smart in most cases. Running away, in small group combat, is generally a very bad idea that is almost certain to result in something horrible happening to at least a significant portion of the group (running away in mass combat is different, because that's all about individual survivability versus the group). In a modern setting where there are high-powered ranged weapons, running the way is often an even worse option because it means giving your enemies free shots.

Historically, in small group engagements you ran away first, and they only chose to fight when that effort had failed, and if you were losing the subsequent fight you surrendered and took your chances thereafter. The calculus was generally that surrendering to someone who had every right to execute you at their whim was still a better choice than trying to flee most of the time. In a fantasy setting, wherein characters fight a lot of things that are totally incapable of even acknowledging a surrender much less honoring one, this option atrophies, and players simply fall back on fighting to the death and hoping.

Rather than trying to force the players to learn to flee, I think it would actually make more sense to try to train the players to surrender instead. Especially because scattering to the four winds inherently splits the party, while being captured keeps them together. In the case of truly overpowering encounters, you can have the aggressor, assuming they're intelligent, utilize non-lethal force to subdue the party (D&D, unfortunately, has mechanical issues in this area) and capture them that way. After all, an enemy that truly does possess 'overwhelming' superiority really ought to be able to capture the PCs without killing them.