Coop is a must for TES 5. If they thought it did well single player, it would do a lot better multiplayer. However do not get me wrong, I do not mean make it so that 80-1024 players can play at once in the world like a MMORPG, I mean make it so that a number between 1 and 16 players can play via a host like system.
All character data is stored locally. Basically should aim for people who want to use it to roleplay. If nescescary allow one player to even have the ability to use consol commands and stuff for creating events like a dungeon master.
Anyway, fights should obviously in that case be much more epic. Instead of like 4-5 unit fights, there should be on average 10-20 unit fights going on. So that you could have groups with tasks and mages with target/touch buff spells which actually have a point.
Ofcourse part of this should allow you to team up with adventuring AI which try and imitate players and who level up as you do.
More random generation would be nice. Infact taking it to the next level whereby seemingly unique individuals are actually randomaly generated and so are the quests which they give (voice acting may be troublesome or imperfect but meh). This would mean that you would actually truly have no end.
Duengeons of epic size would also be cool, whereby they could take hours to wander around with friends, encouraging splitting up.
Some form of renewal, whereby certain areas damaged by quests, events or people you killed eventually get repaired or replaced. This is so that the world does not seem to be become more and more empty as you advance.
Unique wandering enemies would also be cool, whereby they are characters which are also capable of leveling up but will cause problems and mischief, like robbing, murdering, or generally being no good and rude. These badies should use an adaptive difficulty system based on your character, whereby they level faster upto your level but slower above so they never become insanly strong unless your really slow. Also they could be made as reoccuring badies, whereby they still suffer the permant death that normal ones do but will be replaced with new ones and level up from scratch again. They could also be made reviving, whereby they resurrect when they die with some for of penatly. Eithor way this would certainly bring about some more enjoyment.
Also scripted quests should have some form of multiple endings with ballenced rewards on both sides. A good example to where this could have been applied was the dark brotherhood in TES4, whereby you could have the bad ending whereby you became top rank of the group or the good ending, whereby you became a spy working for the imperial legion and eventually have the whole group brought to justice (and get a big ass reward).
Better combat mechanics. TES4 really suffered from poor combat mechanics. All melee weapons acted simlarly with no changes between them next to aoe and rate and damage. All arrows were the same and fired the same. All spells had the same sized ranged projectile collision and shape. All too simlar and boring.
I would like to see a system whereby your sword actually has to contact the enemy for it to damage them and the damage is based on how well it contacted (eg just scrapping a target should do redued damage while in TES4 it did full). Arrow and ranged weapons behave differently and work differently, like the ability to have an automatic crossbow or crossbow instead of always a bow (maybe even a gun?) and their range varies depening on munition and weapon type. Spells should also have a more varied projectile type, eg the ability to make a homing magic bolt, or splitting ice bolt, or fire spew, or buffing pulse (generally more dynamic spells making it more of a joy to spellcast) and make being a mage feel good and not repetitive.
Better armor system. Armor types should have a fine ballence between physical and magic reductions and penalties. Armors may even have subtypes of both which would be even cooler, but for simplicity I will discuss it only having 2. In tes oblivion, waring light armor provided nearly no penaltiy with casting spells, and even full heavy armor did not greatly reduce the effectivness of spells. I would like to see a system whereby there is a fine ballence between what is appropiate to ware trhoguh use of penalties like cast rate and mobility, and nothing is better than the each other. Light armor should tend to be favoured by solo mages, in the magic reducing variety with some physical reduction as it does not lower cast rate much and allows for mobility with decent protection. Fighters should generally like heavy armor, often with high physical reduction and lowis magic reduction (they get hit more physically and have more HP so spells are less effective) as they should seldomly need to cast and speed is not really a problem for them. Light physical attackers like archers should probably go for simlar armor to solo mages as they need mobility but some protection. Team mages however could go for enchanted cloth stuff which could boost their magic power while have no cast rate penatly (however leaving them voundrable which a spell might help cover). This approch would generally be advisable and would add a lot more complex fighting and gearing system whereby a melee fighter may wish to have some lighterarmor with him as well so as to be able to run after someone.
A tweeked potion and alchemy system. The TES4 one was ok I guess however it should logically be made slightly more complicated, with more factors influencing it. When making a potion you could interact with some stationary apparatus which would improve the result. Also you should be able to concentrate potions, combining them together with some other ingredients to enhance thier effect. This points towards perhaps an opperation driven alchemy system whereby you have ingredients and perform opperations with them to produce a product. Potions should be quantified, meaning that each potion has a volume available of which you can specify the ammount that to be used (a poision could be used to poision multiple hits or a strong healing potion only needs a small amount to be consumed) and weight of potion is based on the volume and not ingerdients. More complicated effects would be good, whereby a potion may boost your damage massivly but in a few minutes render you usless in combat for a while. Also your alchemy should produce byproducts (additional unwanted products) or have a chance of failing based on the opperatons used or performed. Also you should be able to find unidentified potions (with no label) which you could analise (reducing volume slightly) or risk consuming. Generally longer potion effects would be nice and seeing AI use them better would be great, eg poisioning a weapon should last for so many attacks (arrows) or so long (melee) depening on the quantitiy applied. All these changes would make potions a really crutial part of gameplay, as physical characters may wish for large quantities of posisons for their weapons and mages for their spells. Being able to create really strong potions could be a highly important skill, as your potions would be far superior to those generically created and have longer effects.
