Friday, November 29, 2019

Surrender

Old school RPG combat is not a carefully balanced system meant for the players to win. It's a high-stakes affair, but its lethality can be mitigated somewhat by giving full consideration to other possible alternatives than fighting to the death. Fleeing is an oft-cited and important option, but there's another one less considered: surrender.

There are many reasons why monsters, particularly intelligent ones, may be willing, even eager, to accept the PCs' surrender. Surrender shortens a battle, avoiding the additional losses that even the victors will likely suffer if they fight on. In the long run, being open to surrender is also a great tactic for gaining more loot at less cost: if the monsters can cultivate a reputation for letting victims live, it encourages future victims to surrender with little or no bloodshed, a strategy used to great effect by real-world pirates. "Your money or your life" is a much more meaningful dilemma if you know your life will really be spared when you hand over your coin.

The PCs may also have more value as prisoners than as corpses. The monsters might keep them as slaves, sell them into slavery to another group, or demand ransom for their release. They might be kept alive as livestock for fresh meat later. Or the monsters might wish to interrogate them for information. Clever players may plead for their lives with promises to reveal the location of something valuable to the monsters. or to perform some unique service for them.

So, why is surrender as an option in a hopeless combat shunned while running away or fighting to the death is not?

For the players, it may be a matter of pride. Surrender may feel like a more ignominious action than retreat. Running away also has the advantage (if successful) of assuring the party will keep all or most of its equipment and treasure, while surrender often results in the losers being stripped of valuables. Finally, there's the possibility that captured enemies will simply be executed, thus resulting in a more certain death than fighting on against long odds.

The DM may be guilty, consciously or unconsciously, of making surrender an unattractive option. A DM who hasn't considered the possibilities or doesn't know how to turn a surrender into an interesting setback rather than total defeat, may steer players away from it. An adversarial DM who punishes the party harshly in-game for surrendering also pushes them toward a binary fight-or-flee attitude. Also, if the campaign is one where death is cheap, with an abundance of options for raising dead characters, the players will likely consider any combat that doesn't result in a TPK to be better than being captured or looted of favorite magic items and such.

How does one, as a DM, begin to reverse the stigma against surrender in a fantasy RPG?

1. Flat-out tell the players before beginning a campaign that they won't be able to win every fight, and retreat and surrender are both legitimate alternatives to getting slaughtered.

2. In-game, feed the players evidence that surrender is a setback, not an irredeemable defeat. Let them hear of a group of traders who surrendered to the local orc tribe and were allowed to live. Better yet, give them a strong example to follow. Maybe they hear accounts of experienced, brave, and respected adventurers, perhaps even mentors of the PCs, who have surrendered to opponents, and who have embraced the philosophy of "live to fight another day" rather than "death before dishonor." Have them recount their memories with pride or amusement rather than bitterness, to drive home the point that knowing when to admit you're beaten is just a part of the adventuring life, not a disaster you'll never live down.

3. Don't summarily execute characters who surrender. This should be so blatantly obvious, I almost didn't include it, but better to be thorough. If you decide the monsters would execute the PCs, at least let them mull their options for escape from a squalid cell for a while before the sentence is carried out. Surrender should be an opportunity to extend the story, not an excuse to cut it short.

4. Really consider what the monsters want out of the encounter. Dead PCs are not always a primary, or even secondary goal. Do the monsters want loot, food, prestige, information, to complete some task, or to protect their territory? Can they get some of what they want with minimal combat losses instead of risking their very existence to get the whole ball of wax? If so, why wouldn't they take it?

5. Surrender does not always have to be unconditional. Allow players to bargain for the best terms. Remember that this isn't an all-or-nothing proposition. Intelligent monsters should weigh the risk of trying to get everything against an easier win for a lesser reward. Not only does this allow the party to limit its losses of prized equipment and treasure, it allows the players to save a little face too.

6. Be prepared to explore the consequences of the choice to surrender. Let them feel the agony of defeat, and then tempt them with opportunities to escape, to regain their lost possessions, to rebuild their reputations, to seek retribution, to use their survival against all odds to rally the townsfolk, or even reach an understanding with the monsters as worthy adversaries. Revenge and redemption can be powerful motivators.

7. Remember that as DM, your goal should be to play the roles of the monsters, not to crush and humiliate the players. It may sometimes happen that characters are humiliated in-game, but the players should never be made to feel hopeless or ashamed of their performance.

Sunday, November 3, 2019

Secret dice rolls

Sometimes you may not want a player to know right away (i.e. at the time the dice are rolled) whether or not a character's action is successful. Stealth and sneaking are obvious examples. Another I'm thinking of is for the prayers and rituals of my Devoted class for Goblins & Greatswords: I want to make the faith element of the class more than just a word, by keeping the rolls secret from the player until actual results are seen (or not seen.) Yet I also don't want to undermine confidence in the objectivity of my GMing.

Option 1: Roll the dice in a box dedicated to the purpose, and leave them until the players have seen the results in play, then reveal. The down side is that those particular dice are out of play for a while, so you'll need extras.

Option 2: Have a different player, whom you can trust to keep a secret, witness the dice roll. This would work best when the other players trust that player, too.

Option 3: For better or worse, we're not living in the 1980s any more, so we may as well make use of the technological advances of our age. Roll the dice in secret, but where the players can hear it, and then snap a picture of the dice with your phone. Have the players record the time and the purpose of the roll. When the time comes, show them the picture -- the time stamp will confirm its authenticity.

Friday, November 1, 2019

Goblins & Greatswords: A new look for the cleric

My much-delayed fantasy heartbreaker, Goblins & Greatswords, is finally picking up some steam, and has given me a new take on a fairly controversial class that's been with us almost as long as fantasy role-playing games have been a thing.

I've opted to call this reimagined class the Devoted (after waffling between that and Dedicated.) I'm trying to avoid using the class names from that other game, and neither "priest" nor "crusader" had the broader feel and connotations I was looking for. I'm not 100% happy with it, but unless I get a better idea, Devoted they shall remain.

Rather than casting spells as clerics traditionally have in D&D-like games, the Devoted can petition the higher powers for boons thought prayer and rituals. It's a bit more limited than wizardly spellcasting, but also a bit more open-ended. The basic mechanic is essentially identical to the reaction roll to determine monster and NPC actions toward the party -- I'm using my own 2d10 reaction table, of course.

Every Devoted can gain Faith Points for dutiful service, up to a maximum of two per level of experience. These are not acquired automatically upon gaining a level, but must be earned through deeds that advance the faith. These may include assisting those in need when it would be inconvenient for the character’s own goals, heroic acts at great risk of life or limb, or defeating an enemy of the faith; the GM will decide how many points each deed is worth. Points may also be lost for acting against the tenets of the character’s faith, but otherwise, a Devoted can always restore his or her maximum Faith Points through a night of rest and a morning of prayer.

When petitioning for divine aid, the player rolls 2d10, adds the character's adjustment for Presence (i.e. Charisma) and as many Faith Points as he cares to spend (announced before the roll is made, not after.) Other bonuses and penalties may apply e.g. for holy items used, the magnitude of the boon sought, and strength of the opposition. The cleric's Turn Undead ability is folded into this system, with a penalty based on the Hit Dice of the creatures to be banished. 


Roll (2d10 + modifiers)
Result
2-3
Request denied; offended. No further requests considered until penance is done
4-8
Request ignored
9-13
Neutral
14-18
Request granted
19-20
Request granted with pleasure; half of Faith Points returned


Possible prayers include:

Banishment: The equivalent of Turn Undead.

Guidance: Similar to the AD&D spell Augury; the player frames a question and if successful, receives an answer in the form of a sign or omen.

Healing: Not the same as instant magical healing, but rather to speed recovery. E.g. instead of curing a disease, the symptoms get better over a period of days.

Warding: Sort of like Protection From Evil (or undead, or lycanthropes, or what-have-you.)

Cleansing: For purification of food and drink, but also for purging spiritual foulness such as curses.

Blessing: Bolstering the character's or an ally's chances to succeed at some feat, or at least avoid harm in the attempt.

The exact descriptions and mechanics for these powers are still in development (i.e. bouncing around in my head) but I think, at least in principle, it's a feasible way to differentiate a faith-based class from its spellcasting counterparts.




Thursday, October 24, 2019

A Wizard's Errand

Around the end of 2018 (Dec. 31 -- the very point of the sting on the wyvern's tail, in fact) I achieved one of my life goals: becoming a published fantasy novelist. Well, self-published, at least. I had been reluctant to talk about it here, perhaps out of some strange desire to keep my game-blogging life and my novel-writing life compartmentalized, but what the hell ... here it is.


Needless to say, with the combination of my shoestring budget and extreme loathing for shameless self-promotion, it hasn't exactly taken the world by storm, but I'm rather fond of it nonetheless. Among the limited readership so far, it seems to be curiously polarizing: some have loved it and written of it in fairly glowing terms, and some have despised it, even to the point that their reviews take on a strong tone of personal affront. (How dare I give away free ebook copies and force them to read such dreck?) It's been described as refreshingly unique (I probably wouldn't go that far, myself) and as a shameless LotR ripoff (which I'm also quite sure it is not, despite some possible similarities in genre and tone.)

At any rate, the truth of its quality probably lies somewhere in the vast continuum between timeless masterpiece and abject turd, though I have some small hope that it leans slightly nearer the former end of the scale. It's meant to be the first of a series of three books (one of those "trilogy" things, I suppose) with the sequel, A Minstrel's Apprentice, currently slogging through its final draft before beta reading. I didn't really set out to write a young adult novel, and I wouldn't necessarily consider it one, but that's probably the demographic to which it might appeal most consistently; whether it's the cup of tea of those 40-somethings and beyond who comprise this blog's readership I leave as a question for the individual.

Thursday, October 17, 2019

Rumor has it

Gathering information before heading off to face the dangers of dungeon or wilderness is always a smart idea for players in old school games. Probably the most iconic example of this is the classic rumor table, as appearing in a handful of old modules from the Holmes-Moldvay era of D&D. My first experience with the concept, as it probably was for a vast number of old school players too, was the rumor table in B2: The Keep on the Borderlands. The idea is valuable and sound, but I can think of some ways it might be better implemented.

First off, some rumors ought to be assigned to specific NPCs, or to certain types of NPCs, e.g. guards, merchants, beggars, and so on. Some rumors can be widespread and available from any fool on the street, but others are more appropriately disseminated by select persons. Not only does this often make narrative sense (the woodsman should know more about the owlbear that's made the local forest its territory, and the merchants' guild officials naturally have the inside dirt on the recent bandit attacks on commercial traffic) it also gives players a reason to seek out and talk to these NPCs rather than idly questioning patrons at the tavern until they're sure you've rolled every possibility on the rumor table at least once.

Secondly, every rumor should reveal a truth about the campaign. Even the "false" ones. I can't stress this one enough. Instead of throwing out random and arbitrary false rumors to mess with the players, think a little bit about why someone might believe a misleading rumor to be true, or alternatively why he might spread it if he doesn't believe it, or even knows it to be false.

1. The rumor is based on someone's actual observation, but is mistaken as to its meaning. A hermit who lives in the woods often sings loudly and horribly off-key, leading to a rumor that the woods are haunted by tortured souls.

2. The rumor is based on someone's observations, and the witnesses have been deliberately misled. A clan of goblins wear boots with ogre-foot-sized soles to leave ogre-sized tracks to scare away interlopers, so naturally the rumor spreads that a terrible ogre will kill and eat anyone who trespasses in his domain.

3. The rumor has a kernel of truth but is wildly exaggerated. The sensational has a certain cachet and staying power that the merely factual often lacks. People love to embellish stories, sometimes without even intending to distort the truth. That quiet fellow in robes who frequents the library and apothecary but says not a word about what he's doing? Obviously a powerful wizard who'll turn you into a toad if you look at him cockeyed. The juvenile dragon that moved into the cave on the bluff with a pile of copper pieces? A world-destroying monster that sleeps atop the hoards of seven kings!

4. The rumor is true, but the NPC relating it doesn't believe it. Sometimes the truth is just too wild to be believed. The rumor, when it is repeated, is told with heaping dollops of sarcasm, scoffing, and eye-rolling. Those who do believe it will probably be mocked, and the person who started it may be a laughingstock in the community.

5. Confirmation bias. The facts of the case are more or less agreed upon, but minor details and interpretations are twisted to reinforce the teller's pre-existing opinions. A local outlaw claims to be the lost heir to the throne. He's definitely working to undermine the current king, but is he an impostor trying to usurp power, or the rightful ruler here to depose the tyrant? Depends on whom you ask.

6. The rumor is started by someone seeking attention. While other attention-seekers may pass it on as second-hand news, the players won't find many other witnesses who can corroborate it directly. It's probably best used as obvious comic relief rather than a serious lead. Naturally, these are almost always complete rubbish, but once in a while, such a rumor could turn out to be mostly correct, to the surprise of everyone, including the rumormonger.

7. The rumor is started by someone who stands to gain from it. Said person might actively perpetuate the hoax by staging or planting evidence to be found by others. An herbalist might put out a rumor of vampires to sell garlic, a king may sow rumors of invasion to scare the populace and justify draconian rule, or a crooked merchant might tell of a treasure in a nearby cave, where hired thugs await to relieve treasure-seekers of their equipment and lives.

It should be noted that many of these possibilities reveal more about the people who spread the rumor than its actual subject, and those kind of things have their most interesting and useful effects in a campaign in which those people are recurring characters. It's more fun when players can develop a sense of which NPCs can be relied upon, which ones are deceitful, or gullible, or concerned about their image more than the truth.



Wednesday, September 25, 2019

The monstrous Other

Over the years of reading RPG blogs, I've seen a lot of musings about the portrayal of certain monsters in D&D. I've seen the "baby orc" moral dilemma hashed over quite a lot. A few times, people have argued (with very little justification, in my opinion) that orcs and other monstrous humanoids represent human cultures, and therefore the use of them as Always Chaotic Evil opponents was in some way an expression of latent racism in RPGs and their players. I've seen arguments (with a lot more justification) that the monstrous humanoids, at least as typically represented in adventure modules and supplements, could easily be reskinned as barbaric humans, and thus aren't terribly interesting.

Gygaxian naturalism is a strong force for this sort of anthropomorphizing of creatures. Indeed, as much affection as I have for module B2: The Keep on the Borderlands, the goblins, orcs, kobolds, and other inhabitants of the Caves of Chaos are virtually indistinguishable from savage humans. They reproduce and rear young like humans, they eat and drink like humans, the form social structures like humans. They're just mean and ugly. One gets the feeling that if they only cleaned up a bit, learned some rudimentary etiquette, and abandoned their prejudices toward humans and demihumans (and vice versa), an orc or goblin from the Caves could stroll into the tavern, order a pint, and swap tall tales with the other patrons and not be too far out of place.

I don't believe there's anything inherently wrong in running a game with these interpretations of monsters, but it's not to my taste at this stage in my gaming life, nor do I wish to reskin them as various sorts of human antagonists. What I'd rather do, in most cases, is make monsters truly distinct from humans. An encounter with goblins or orcs should be substantively different from an encounter with brigands or bandits, and each humanoid kindred should be different from the others. Moreover, there should be reasons why these creatures are so often in conflict with humans and demihumans besides mere prejudices and cultural differences.

How do we do that?

One way is to give monsters biological needs and drives that are dangerous or abhorrent to humans. Take orcs as an example. Perhaps orcs have a physiological need to consume the flesh of sapient humanoids. Orc whelps aren't innocent babies but voracious little bastards who need human or demihuman meat to grow. Even orc adults, if they don't taste man-flesh once a month or so, begin to lose even their already limited capacity for intelligence and cooperative behavior, becoming more and more feral and savage, eventually resorting to cannibalizing their own kind to sate their hunger. Whether you consider this to be evil or "just the way they are," it's pretty clear that orcs are going to have a hard time coexisting peaceably with men, elves, and dwarves, and often even with each other.

Another way is to avoid ascribing human emotions to monsters. Humanoid creatures need not experience the same range of feelings, nor to the same degrees or for the same reasons, that humans do. For example, they might be constitutionally incapable of empathy or compassion, similar to human psychopaths. Such creatures could have an instinctual drive to preserve their own species, while being utterly indifferent or even malevolent toward others. This seems especially appropriate for non-mammalian humanoids, such as lizardmen or troglodytes. Lizardmen seem like good candidates for an apathetic-psychopathic personality, while troglodytes could be the more actively sadistic serial killer type profile.

Emotions could be even more radically different in various ways. Loss may induce laughter, affection might be dysphoric, hostility breed attraction, or kindness lead to revulsion.

A monster's alien biology may not be inherently hostile to human life, but may give it a radically different perspective. Consider "dark fey" type creatures, which are not born of two parents and reared from infancy to adulthood, but instead are spawned from elemental, magical, or psychic forces, awakening from the oblivion of their previous nonexistence fully formed. Such creatures have no concept or understanding of family bonds, no experiences of the innocence of childhood, maybe not even of adulthood or old age or stages of life generally. Not only are there no "young" monsters with which to impose the tired "baby orc" dilemma on players, these creatures would perceive no difference between children, adults, or elderly humans other than sizes and outward appearances.

In my dark fey series, I reimagined several creatures as embodying specific negative human traits, such as envy and avarice. Coupling this with the abiological origins described above, there's not only a very strong reason why these creatures behave in ways that seem irrational, or at least irrationally intense, to humans, but also a reason why creatures of the same type have the same very limited range of ethics and personalities. A goblin isn't mean and envious because it's a goblin; it took the form of a goblin in the first place because its spirit is mean and envious. Spirits of different origins and character might become hobgoblins, kobolds, pixies, or sprites instead.

Or, consider monsters who are born as humans, but through magic or curses or just the natural order of a fantasy world become monstrous in body and soul. Maybe ogres were once beautiful humans who were manipulative, spiteful, and ugly inside, and their bodies transformed to match their twisted souls. As hideous ogres, they're banished from society, lacking both people to manipulate to fulfill their emotional needs and the charisma to do so. Consequently, they become even more hateful and cruel, and probably extremely jealous of attractive humans. Beauty, to them, becomes a reminder of what they've lost, and thus a heinous sin.

Radically different physiology and psychological and emotional experiences might give monsters a blue and orange (as opposed to black and white or shades of grey) moral outlook. To dragons with a pathological (by human standards) love of treasure, theft, or even (gasp!) destruction of treasure may be a far more serious offense than murder. A gentle touch among orcs may be a grave insult, while a punch in the gut is a jovial greeting. Maybe destroying corpses is seen by some monsters as blasphemous, while reanimating them as undead is honorable. Capriciousness may be valued, while steadiness is disdained. A monster may be forbidden by its moral code to lie to a being wearing a wicker hat.

It's possible (and fun!) to combine some of these distinguishing characteristics. Take the doppelganger, a faceless, featureless, genderless being: Maybe the reason it takes the forms of humanoids is because it craves the experience of having an identity. It's not that it feels happy when it takes the form of an individual or sad and empty when it doesn't; it's more like an addiction or compulsion. The creature literally feels a euphoric high by duplicating someone and disposing of that person. While in its stolen form, it does things that seem cruel and evil to humans not out of some desire to be evil or inflict pain, but because its mind is totally alien to the human experience. It may keep its cover for a while by aping their behaviors, but it's apt to apply them inappropriately, and eventually is exposed or driven away, loses its grip on its new "identity" and starts the cycle again.

Whatever traits you apply to any particular monster, players encountering it should feel they're dealing with something inhuman. Negotiating with monsters may be an exercise in thinking way outside the box, and employing them as henchmen is an adventure in itself. It's certainly a challenge, as a human DM, to play the roles of beings who think, act, and feel in ways humans habitually don't, but it can go a long way toward making monsters more than just another faction to deal with or one more set of stats and powers to best in combat.


Wednesday, August 7, 2019

DM best practices: Transparency, or Down with the DM screen!

Over many years of playing D&D and reading OSR blogs, I've developed some pretty strong views on DMing. Many of these thoughts have to do with transparency at the game table. DM screens have long been considered an essential piece of equipment by many, so obviously a lot of other people consider the transparency vs. secrecy issue important. The truth (as I see it) is that screens are often more of a hindrance to good gaming than a help, and most of the stuff that goes on behind them ought to be done in the open, for all to see.

DM transparency fosters player trust. The less you hide from the players, the more they can have confidence that you're not secretly screwing them or coddling some particular favorite character, or the entire party. They'll become better players when they can clearly see how their decisions play out through the impartial application of rules and dice rolls.

But transparency also enhances the experience of the DM, too, by removing some of the temptation to fudge dice rolls in pursuit of a predetermined narrative. If you want to tell stories with total narrative control, write some form of traditional fiction. D&D is a game, not a novel, and a large part of the fun for both players and DM is seeing how things turn out in often unforeseeable and unexpected ways. DMing is a different skill set to writing. It's learning to roll with the punches, to adapt on the fly as you incorporate the results of the players' choices, the rules of the game, and the roll of the dice into the emerging chain of events. You can't develop the skills of a good DM by exercising the control of a novelist, and so you deprive yourself and your players of a lot of the uniqueness of playing D&D vs. writing or reading a book.

Below are some of my guidelines for DM transparency -- all of which, at some point during my DMing career, I was in the habit of routinely violating, and thus providing me plenty of first-hand experiences on which to reflect over the years.

1. Roll dice in the open. Whether it's attacks and damage, saving throws, or wandering monster checks, there's no reason why the players shouldn't see the roll. If it's something that a player really shouldn't know immediately, leave the die alone after the roll if possible, and show it to the players after the situation is resolved. (Even then, it's possible to handle rolls such as a thief's hiding and sneaking in such a way that no secrecy is needed -- for instance, roll only when someone is in a position to notice the thief, and thus the result is immediately known to the player.)

2. Don't roll dice unless you intend to abide by the results. Rolling and then disregarding the result gives the players the correct impression that the dice don't really matter; you're going to overrule them whenever they don't produce the result you want. If the outcome of some proposed action is abundantly clear to you, don't dilute the authority of the dice by making a pointless roll. Own that decision, and announce it without touching the dice. "DM fiat" like this is perfectly acceptable in many instances, such as reactions and wandering monster checks, and at least less problematic in cases when you just want to cut the players a break. (Frank Mentzer gives an example in his Basic Set of a character with 3 hp being attacked by a monster using a 1d8 damage weapon, advising the DM to roll the dice and then announce 2 points of damage, whatever the actual result. I think this is terrible advice. If you must be lenient to a new player, make it clear that's what you're doing, and leave the dice out of it. Own it!)
Also, don't roll dice just to make players nervous. Don't roll for encounters if you intend to just choose whether one will occur or not, or indeed, have already decided it won't.

3. Be clear with the players about the odds of success when they want to try something not explicitly addressed in the rules, at least as far as their characters would be able to observe and discern. "You estimate about a 75% chance of leaping over the chasm." "If you try that, you'll need a roll of 5 or better on 1d6." "No, there's no conceivable way that could work, and you'll almost certainly die if you try it." Then stick to that assessment. "You're not sure if that would work or not" is an acceptable answer in cases where the characters would truly be unable to assess the odds, but that should be an uncommon scenario, and a strong signal to the players that they might need to seek more information.

4. Don't make it arbitrarily impossible for players to gain information. Allow them to discover it when their actions would reasonably be expected to reveal it, even if their learning it spoils some big plan of yours or takes things in a direction you didn't anticipate. If they search the right area, they find what's there to be found. If they ask the right question, and the NPC would know and has no motive for withholding the answer, give it to them. If you feel players haven't been specific enough in describing their actions, prompt them to be more specific -- "How exactly are you examining the wall? Visually only, by prodding with a stick, or touching it with your hands?" -- but don't pixel bitch and don't expect them to read your mind.

5. Don't play "Gotcha!" Provide clues and foreshadowing of danger, so players can make informed choices. Clues don't always have to be blatant and in-your-face, but it should be possible to notice them with reasonable efforts and possible to deduce their meaning and significance. Number 4 is very much in effect: If players do something that would reveal the presence of a trap or hazard, it's your duty as DM to allow them to find it, not create rationalizations for not revealing it because you're so proud of your design and would feel slighted if you don't get to spring it.

6. Don't cut corners, and don't "guesstimate" after the fact. Do the math! I've known DMs who will look at dice rolls and decide ex post facto whether or not they succeed, which is a gross misuse of dice. This could be due to simple laziness or to an unspoken desire for a certain amount of "fudge factor" to allow for DM fiat at the margins. Either way, it's bad form. Could be considered a corollary of Number 2 above: Don't have players roll dice if you're not going to abide by the results, objectively and consistently. As a sub-corollary of this point, don't fudge monster stats in the middle of a fight to nudge things in the way you want them to go. You can faithfully count every pip of the dice rolls, but tweaking ACs or hit points en media res is having exactly the same effect as being fuzzy with the pips. It's just moving the goalposts in a different way, and it's a dick move.

In summation, there are some things that are rightly and properly hidden from the players, and it is the DM's prerogative alone to know in advance, for the sake of an exciting and entertaining game. By all means, do keep setting details (e.g. dungeon maps, the locations of monsters and treasure, the monsters' motives, the villain's plans, shocking details about the setting's history, the identity of the true heir to the throne, and so forth) secret -- but only until the players discover them in play. All of it ought to be discoverable in play, and everything that happens to the characters should be transparent. Players ought to see the rolls that determine their characters' fates, including all the attack rolls, damage rolls, and saving throws, both their own and those of their opponents.
.