Below are the concepts that would have to be included in a MMORPG in order for it to match my vision for what an MMORPG would look like if it were made to appeal just to me. I don't know if anyone else would at all like a game that would incorporate all of this, but that's not the point. It's not a roadmap for a popular MMORPG, but just for the sort of game I'd like to play.

World Details

Most of the world details assume that the game bears a lot of resemblance to Minecraft. Hopefully better looking, and with smaller workable chunks, but those are secondary to the below requirements. In fact, the game could easily be done in a more abstract, less 3D way and possibly be even better than an immersive environment.

Persistent Change

Not only would you as a player be able to change things here and there, but the entire world would be constructable/destructable as in Minecraft.

Large Biomes

Biomes should be no smaller than an order of magnitude smaller than in real life. Micro-biomes can occur inside of larger biomes. If NPC peoples exist, then some biomes should reflect the duration of these peoples upon them. (When colonists came to the new world they were astounded to find that there were large clear areas very suitable for planting… not realizing that these areas had been cleared for exactly that purpose by Native Americans cultures that had died off from smallpox).

Resource Availability

Resources would be relatively difficult to come by (as compared to Minecraft), in order to create scarcity, so that no player could play a character as an island, and be grandly successful. A player might be able to play a character as a hermit and barely survive, but even that would be difficult, often necessitating interacting with other players at times to avoid going without some basic needs. To create this rate of availability requires several things.

Distribution

Many resources, such as valuable minerals need to be set apart in distance/time, such that one can't find everything one needs within a short walking distance. Many such resources should be in pockets where they are relatively less rare, but then pockets should be rare.

There may be clues as to where to find these sorts of resources, such as them occurring more in one terrain type than another.

Renewables

Renewable resources, such as crops, take a considerable time to cycle through their renewal periods, such that overabundance becomes more rare. The renewal processes is faulty so that a proportion of attempts to renew fail. This can be based on effort at tending to the renewal process to some extent, or in taking extra preparations, but any effort will never be 100% successful.

Diminishing Returns

Eventually the base resource, such as soil for crops, will become depleted, requiring something like fertilizer in order to keep the renewable process viable. The only actual perpetually provided resources are sunlight, air, and water. And even these might have shortages at times (volcanic eruption blocks sunlight, drought leaves little water).

Long-Term Renewables

Trees, and other such real world renewables takes an extremely long amount of game time, and thus not be renewable in any practical sense for the one using the resource. Any renewal efforts of such resources should only be beneficial in posterity. So while trees may be a common and abundant resource in an area, the area can soon be cleared out, leaving players to have to go further and further to get the resource in question. Really no different than any other non-renewable.

Extraction Effort

Most importantly extraction of resources takes considerable effort. Both in terms of time and energy. There are ways (see below) that the time element would be made to be non-boring.

Magic and Tech

I like fantasy, and I think it adds a dimension of gameplay to such games (my reasons are actually far more complex, but I don't want to get into them here). As such, the game world will have sources of supernatural power, and characters may learn how to tap into said power.

To the extent that players may understand how to make things that their characters would not, the game will not have mechanisms or resources that allow these things to be built in general.

Single "Server"

All players play in the same game world. This eliminates the desire players have to move resources from one server to another, which can disrupt economies. On the other hand, if new versions of the game engine evolve, these will get new servers, and players may be allowed to migrate one way, once.

Gameplay

Character Existence

Birth

Characters arrive, full grown and capable people, as exiles from “The Old World” (basically medieval Earth) via gates scattered here and there over the world of play. Players can concoct whatever reason they wish for why their character was exiled, but there's no returning through the gates, and so no way to verify these things.

Gates are set up far apart from each other, far enough to make it likely that multiple communities will develop.

Death

Dying is a big deal, often meaning the end of the character as a functional character. The character can continue on as a spirit of the dead in some capacities, however, and it IS possible to revive a character. This can be done by a player diligently questing in the underworld to get back out, but this is a potentially VERY long process (on the order of months of game play). A shorter method of return is to have living characters of other players quest into the underworld to retrive the character in question, but this may in fact result in their characters getting trapped in the underworld. And it is a major undertaking requiring a LOT of resources, even it it is successful. The idea is to make it so that only VERY valuable members of a community who have given a lot to it would have a chance of having that community coming after them.

Phasing Out

A player can have their character “Phase Out” at any time. Apparently when coming through the gates into exile, the character becomes only semi-real, and exists in a parallel world of their own that interacts with the main world on certain levels. Phasing out occurs automatically when a player logs off, but leaves the character active so that the character can continue to work on certain sorts of projects safely (including certain limited interactions with other players' characters). On the other hand, a player may stay logged on and watch their characters automated progress if they like, and phase back in at any time. The conceit, however, is that the PC cannot see much of the world around them, only those things related to their automated tasks.

Yes, this can potentially be used to avoid danger to the character, but this is only limited in effectiveness. First, it takes a few seconds to phase out, during which time the character can't defend themselves (which can easily be fatal, if under attack). Second, the character stays visible to the other characters and monsters while phased out, so they may well stick around and wait for the character to phase back in. A good automation routine for a phased out character will return them to a relatively safe area, therefore.

Basic Needs

Characters would require basic needs to be met in order to survive and thrive. This begins with being able to breathe, needing food and water, and a variety of foods, lest the character get dysfunctions like scurvy. They would also need shelter from the elements, or face injury or death from exposure. Medicines would exist, without which common diseases might become debilitating or even fatal.

Again, it may be possible to survive with limited amounts of all of these, but this would make the character relatively ineffective (see energy below). Players should NOT have to spend a lot of play time obtaining these needs, but they definitely feel the need to set them up.

Basic Capabilities

While some characters may be marginally stronger than others, no character can carry unrealistic amounts of stuff. There may be magic that allows for greater carrying capacities, but the basic capacity is meant to be realistic. Character movement speeds are realistic, allowing for running, but this using up energy fast.

Energy

Characters have a resource called energy which they burn up to do most any action. Energy recovers over time, but only if the character is well-fed. This is similar to the Minecraft hunger model, except that energy fluctuates by itself, and hunger goes down more slowly. You do not eat to recover your endurance, you eat so that you CAN recover your endurance. Being low on energy, and still attempting things that take energy, damages health, and is limited in how frequently you can do it by the character's willpower. A player can over-ride willpower for dangerous situations, when low on energy, but this does even more damage. Characters eventually pass out if this is pushed too hard. If they starve while unconscious, this can lead to death.

Non-boring Resource Gathering

Players who find going through the motions of resource gathering to be interesting or worthwhile for whatever reason, can do so, and obtain modest efficiency benefits from doing so. But for other players who are not interested in these sorts of activities, they can set up production cycles for resources that occur over time, slowly when the player is online playing, and at full-speed when the player is offline. This incentivizes players to take breaks and lessens server impact.

"Deals"

Players may create deals between each other that are essentially regularly occurring trades of things. These can even be baskets of things. In this way players can set up stores where players buy “groceries” and whatever else they might want to purchase for basic needs. Trades for anything can be made, but the primary reason for the existence of deals is so that players can obtain their basic needs relatively simply. One can obtain their needs without the existence of stores, but they would then have to have deals with each provider directly, and so stores would become likely as a source of convenience.

Crafting

Players may discover large numbers of things to create. Enough so that, given the scarcities, that players will likely be forced into a specialty, and may become known for that specialty. Generally specializing is efficient, and generalizing is inefficient. Characters may have secondary skills to their primary specialization, but these will tend to make them hobbyists in these other fields, as compares the specialists.

Character Development

NO LEVELS! Characters develop mostly in terms of skills, and sometimes with slight gains in attributes. But at no time ever will any character be so physically potent that they do not fear the wrath of another player's character, who might sneak up and stab them fatally in the back. And they certainly cannot withstand a group of determined individuals seeking to incarcerate or do harm to the character.

Baddies

There will be some predatory fauna in the game, but these will NOT “respawn.” Once dead, they are dead for good. They will also tend not to rampage much in the areas around gates, so they're not that much of a threat to communities. They will be a threat, however, to those ranging far out in order to find resources.

Otherworlds

There will be gates to otherworldly places, where characters can go on relatively dangerous quests, often with magical rewards (see Heroquest). The static nature of these worlds explains their “instancy” nature… though with enough effort, even the instances can be altered permanently.

Social Engagement and PVP

Many of the above conditions are attempts to create a somewhat “realistic” model of the world precisely so that realistic social interaction can occur. Players should keenly feel the need to interact with other players' characters to get not only what they want, but what they even need to survive. Such that any character going rogue and attacking a valued member of a community will become themselves at best outcast, and perhaps hunted down. Death being a real impediment to play, this should deter people from frivolously attacking others.

Conversely, being a credit to your community will keep you safe, as those who see the character as valuable will try to protect it. Given that one character is likely to be killed by two or more, banding together is the best way to stay safe. If you are valuable enough, the community might even mount a rescue of your character from the underworld, which mitigates having been killed.

And, as a last ditch, one can phase out if one is in serious trouble. Though this may leave their un-carried belongings unprotected.

It is, of course, possible that griefers may appear, who kill PCs, and then, when their character is inevitably killed, simply make a new character and try again. Given this possibility, players may well be paranoid about those who appear from gates, and may come up with protocols before accepting new players into their communities. The characters are exiles, after all, and it's assumed that some are dangerous criminals. Communities are likely to form at first between players who are friends who recruit players in real life, so that they know the players in question are trustworthy.

The model is set up so that you either learn to live socially with others, or you find your game-play to be severely curtailed.

Warfare between communities is a likely possibility, and one for which players will have to prepare, or risk character death, and all that they've built being stolen. Characters who are set up productively are a premium resource in the game, however, and thus one hopes that players would be able to see this, and refrain from killing. In other cases, players can endeavor to simply move far enough away from potentially violent communities, perhaps in secret.

In the end, however, what strategems and tactics players end up employing will likely be emergent. Rules will rarely be changed for the game, even if degenerate strategems evolve, instead having new servers emerge later for those who might like to migrate.