The following is a quick summary of my ideas that are different from Daggerfall. You can ask if you're interested in details.
- Players are able to make spells on their own, without using services of NPCs. Every spell is composed from basic spell parts and players are free to modify it. There is a whole spellcasting language for it, but it's a character who needs to know it, not player.
- Inventory is not some place where characters keep their belongings, it's a list of what the character understands as belongings, even if it is currently lying around. As such, your house can be a big inventory. But to take it outside player must pack or wear it, or simply hold it in hands. The purpose of the inventory is to make the process more manageable. It also allows creating plans for automatic usage of items, like which food should be eaten and when.
- Diseases and other status effects, as well as any information that might be limited by character's understanding require a properly developed skill to be displayed correctly or at all. If character doesn't understand it, player doesn't see it. I generally would like to change what player sees depending on what skills and status effects character has.
- Stats like skills and attributes are fragmented into many mini-stats, each specializing on its own thing and having only three levels. They rise from usage, but also depend on unique for each of them conditions to grow faster. They are deterministic and do not involve chance for their actions.
- Instead of things like Health or Spell Points, there is Attention meter. Each action takes some Attention, how much depending on the level of skills this action is based on. If you can't spare the amount of Attention required by an action or a defense from a hostile action, it will be successful only for the part that got enough, the rest of it just fails, turns the part that was successful into something undesirable or lets hostile action negatively affect the character in the case of defense. Each type of injury is its own thing. While normally Attention quickly replenishes to its maximum, negative status effects can slow it down or take a fixed part of it. One of the most common such negative effect is fatigue, others happen when characters neglect their natural needs. Characters have many needs, but most mundane ones do not require player's explicit attention and are done automatically if the environment doesn't prohibit it. Death occurs only on failure of vital organs, but many effects can lead there in a roundabout way unless treated in time.
- Combat gameplay mostly revolves around using environment as a source of energy or catalyst for various effects, with less focus on using weapons. In the most basic form it's making sharp and heavy (or in other way dangerous) objects collide with enemies or pushing enemies against such objects. More advanced form is chemical reactions, achieved by using objects at hand or with the help of magic. The most advanced form is using an output of one reaction as the source of energy for another, extensively exploiting chain reactions. Each fight should have at least some element of a puzzle.
- Being able to pacify and speak with enemies is a much bigger part of the gameplay. Although inhabitants of the world are mostly generated, all of them have personality, their stats are fixed and they can be found in the same place and time across different playthrough, unless something disturbed their routine (or if they were regenerated with a different seed). Therefore, a particular NPC's character development due to player interacting with it can be reproduced on a different playthrough and would be unlike that of another NPC.
- The story of the game can be influenced by interacting with such NPC's. Or it can be left alone, because it will still progress, and player's role will be a spectator.
