I've got a pretty detailed concept for my perfect RPG in mind, and one day I'll create this beast, no matter what it takes.
Essentially:
Setting:
- low fantasy setting, humans only, no elves or dwarves, but plenty of hostile fantastic creatures to fight when you crawl through dungeons, as well as sinister magic-users; tech level is somewhere between late antiquity and late middle ages, with some civilizations being more advanced than others
- cultures: Germanic style kingdom is the realm where the game happens, it used to be part of a Roman style empire but was lost barely a century ago; sturctures of the Empire remain in the kingdom, because why would the king not make use of the experienced imperial bureaucrats? To the east, the land is often raided by Amazon style horse-riding women, who are slowly settling down though and becoming more "civilized" as time goes on
- different weapons that correspond to each culture's tech level and fighting style, with the horse-riding girls using spears and bows and often fighting on horseback, Germanic kingdom focusing on European medieval style warfare with chainmail and a huge variety of melee weapons as well as crossbows, and the Empire to the south having efficient mixed-arms tactics with orderly shield wall formations, each soldier carrying sword + shield + javelin, they have light artillery for support (ballistae etc), and even have primitive handcannons
Combat:
- turn-based combat with lots of tactical options, each weapon actually feels different and has multiple uses, shields can be used offensively, swords can slash or thrust and even pommel-strike, halberds can attack with the pointy spear tip or the axe blade or the armor-piercing spike, etc. Whether you go for a warhammer or a mace or an axe or a sword isn't just a cosmetic choice but actually gives you distinct tactical options
- mounted combat is in, with options like charging with a lance or doing a ride-by attack, rider and mount have their own HP pools and the mount can be killed to topple the rider down, or the rider can be shot down from his mount
- locational damage, locational hitpoints, a common "blood pool" instead of overall HP, critical hits on an already damaged body part can cause permanent injuries (crit on an already damaged hand -> chop off some fingers or the entire hand, crit on damaged foot -> chop off the foot, crit on face -> lose an eye or lose your nose, etc)
- management of blood loss, injuries, stamina, pain threshold, morale etc instead of whittling down hitpoints; lose all locational HP on your leg through a warhammer hit, your leg's broken and you fall to your knee and won't be able to get up again during this fight, also it hurts like fuck which gives you a malus
- some weapons have multi-step reloads; crossbow = wind it up 3 AP, put in the quarrel 1 AP; handgonne = pour powder down the muzzle = 2 AP, put bullet in = 1 AP, use ramrod = 3 AP; this way you can partially reload your crossbow or handgonne even when you don't have enough AP left for the full action
- useable defensive weapons like stationary artillery, such as small ballistae to pump bolts into advancing enemies, as well as environmental features that can be utilized in combat (knock over a brazier to set fire to the carpet, for example)
- equipment can get damaged but it's not just a numeric health value, instead clothing may get torn and cut when hit with bladed weapons, plate armor can get bent, chainmail can get chain links ripped out of it, a sword can break, but all of these still stay useable even when severely damaged (they're just pretty useless - you can stab someone with a broken sword but it's a shit-tier weapon, chainmail with several chain links ripped out won't offer much protection anymore)
Character and party:
- detailed equipment system similar to Daggerfall and Morrowind, with tons of equipment slots and layered clothing and armor; find armor not as a full suit but in single pieces, have several layers of stuff to wear, starting with underwear and going up to two armor layers; lots of slots for jewelry, including a ring on every finger, and female characters even get to wear stuff like earrings, anklets, and toe rings
- major differences between playing a male or female character, as NPCs will react differently to you based on your sex, and some quests are gender-exclusive, the experience will be quite different
- NPCs will actually react to your appearance when appropriate, and you can disguise yourself by wearing the proper clothes, maybe you even have to get a different haircut; infiltrate an order of monks by shaving your head and putting on a robe in the proper color, impersonate a high-ranking member of the order, and get away with it if your character is skilled enough at disguise
- you can choose personality traits for your character that directly influence character skills and dialogue choices; playing a berserker with the "wroth" trait may give you a great bonus in combat, but when an NPC insults you all the dialogue options you get will be ones that escalate the conflict, you won't ever receive any dialogue choices that let you back down or resolve a disagreement peacefully -> meaningful character choices that actually force you to roleplay the character you created
- you create a single character and recruit NPCs for your party, like in Baldur's Gate and Arcanum; of course you get to control companions in combat but they might refuse your orders if they're contrary to their personality (the timid healer girl isn't going to walk into a tile that's surrounded by 3 enemies, you won't be able to use her as a charging melee character)
- companion NPCs actually have their own agendas and goals; that seductive sorceress you recruited and thought you'd get a nice romance with? Well, you got a room in an inn together, and when you wake up the next morning she's gone... along with your gold and magic items, oops. That ambitious fighter who joined you to help in your quest if you agreed to help him in his? Well, it's been two weeks and you haven't even bothered to do anything at all about his quest, so he's leaving your party because he doesn't see any progress in his goals while he's with you
Magic:
- a magic system that relies on environmental factors and has spells with interesting effects rather than just simple damage spells; elemental magic is divided into the masculine and feminine elements: air and fire, earth and water. Only male wizards can use air and fire magic, only female wizards can use earth and water magic, making male and female wizards play radically differently
- elemental magic can only be cast when the wizard is in direct contact with the element; air magic is more effective under the open sky than in a deep dungeon; fire magic requires a source of fire to be in the wizard's immediate vicinity that he can touch with his bare hand to channel power from; female wizards essentially have to ditch their shoes and socks and go barefoot everywhere, as they need direct contact with the earth to cast earth magic; works better in nature than in cities where the stone has been hewn by human hands; and water magic requires a sorceress to stand in a puddle, or in a larger body of water; positioning will be extremely important for magic-users in combat, since you always want your male wizards near a source of fire and your female wizards standing on bare earth or in a source of water
- apart from elemental magic, there is also ritual magic which requires ingredients and lengthy preparation; there are few ritual magic spells that are usable in combat, but those that are require multiple turns to cast, making the caster vulnerable
Quests:
- quests should offer multiple approaches and solutions, usually offering a combat path, stealth path, dialogue path, and alternate solutions for magic-users or creative players who use items and the environment in creative ways
- non-linear main quest which gives you a goal from the outset (find a cult of evil witches and stop them), and you essentially get free reign in how to achieve it rather than having to follow a series of main story quests
- if you do it properly you can work for two factions that hate each other as a double agent, and cross both of them for maximum personal profit; lie and deceive your way through the game and make heavy use of those speech skills you invested points into
- on the other hand, you can piss off questgiver NPCs to the point they no longer want to associate with you or even actively send people to deal with you, so you have to be careful; NPCs have their own agendas and use you as a tool, if they consider you an obstacle, they will be hostile
Dungeons:
- interesting encounters both of the combat and the non-combat type
- environmental interaction within dungeons, such as shoving a mine cart filled with rocks down a slope into an enemy crossbowman standing there, etc etc
- occasional adventure game like item interaction puzzles to get into optional areas of the dungeon that seem impossible to reach at first glance
- interesting dungeon design offering cool combat options, such as a bandit fort with palisade walls that can either be climbed or the gate breached, elevation bonus for enemies on the walls, you trying to get the high ground etc, or an underground lake with a giant octopus-like tentacle beast fighting you from the water while land-based monsters attack you from the flanks and try to push you towards the lake, etc
NO HANDHOLDING:
- the game will likely start out with a couple of introductory quests that show the player the options he has, like changing his appearance to impersonate someone else etc, but after that, the player is completely on his own and has to figure that shit out for himself -> you want to infiltrate an order of monks? Observe them, read about them, find out how they dress and what their manners are, prepare yourself meticulously, give yourself a tonsure haircut, wear a brown robe, tie a black rope belt around your waist, and pretend to be a high-ranking member visiting from another city... only for someone to call you out on your bluff because high ranking members wear a differently-colored rope belt, oops; you have to find out such details by yourself, the game won't hold your hand and protect you from mistakes
- no quest markers whatsoever, NPCs will describe to you how to get to a place, sure you have a world map but it's just for overland travel like in Arcanum or Baldur's Gate, when someone tells you to go visit John Doe at 17 Smithers Street, you won't get a map marker but have to go find the address yourself
- when NPCs mark a place on your map they might not always be 100% accurate, maybe someone will mark the Ancient Crypt on your map and be off by a couple of world map tiles because he misremembered the location
I really, really hope I get the opportunity to create this thing one day. Probably didn't even list everything here yet.