"Realism" can mean many things to many different people, and these are just a few of my "peeves" with situations where realism is either needed or is applied in a way that breaks immersion or gameplay:
Gold should have weight to avoid unreasonable amounts of cash being carried, but there should also be items (gems, jewelry, works of art) that have a much higher value-to-weight ratio, so you don't need to carry 200,000 Septims around with you.
Yea on that a thought was to simply have the coinage in different values like copper, silver, cold and platinum. Also coins could have a higher markup value than 1.
Also Letters of Credit would be nice to have for large sums of money, possibly even able to trade them for other letters, in fact paper money was created that way.
NPCs should have jobs, and occasionally DO them. Morrowind had a decent number of farms and mines, but the slave laborers were on perpetual break; they never actually lifted a spade or shovel. Oblivion had working and believable farms just outside Skingrad (I believe there was only ONE other farm in the entire game that actually funtioned, even if the farmer was invisible), but was there even a single mine that wasn't merely a Goblin den?
Exactly, we never saw fishermen to go out and fish, hunters actually hunting AND bringing back their game. Carpenters and smiths actually working on things.
And guess what, GOTHIC, a game that came out several years before that, had NPCs actually working on things and even MAKE things, a smith didn't just hammer on a anvil randomly, at the end he actually created things.
Supply had no effect on price in either MW or OB, and there was absolutely no demand other than by the player. You could sell a weapon or piece of armor to a merchant, who would pay the same price for it regardless of whether it was the only one in the game or if he had 20 of them in stock already. That turned the already unrealistically easy and lucrative selling of home-made potions in MW into an outright game-breaker, since the same merchant would buy 200 of them at full price, even after buying 600 of them previously over the last week of gametime, while never selling a single one of them over the entire course of the game. The odd concept of merchants in OB having unlimited amounts of gold, but not be willing to spend more than a set amount on a single transaction was also absurd; the ability to "barter" goods to sell items for more than a merchant's current cash-on-hand was a huge plus.
Merchants should have a limit, not just how much total money they have but how much inventory they are willing to buy and WHAT they are willing to buy. A clothing and garments salesman will not buy your swords... scissors maybe.
A good idea there would be setting up your own store and putting the stuff you get on display to be sold over time for possibly a better price than you'd get from other traders.
Food, drink, and sleep could be included in a manner which makes it preferable to deal with them, but not absolutely essential. That would slightly reward those who choose to mind the details, but not severely punish those who couldn't care less about it. Having food as "healing potions" that instantly restore hitpoints, like in FO3, is simply not "plausible".
Food, water and sleep could be necessary to upkeep natural regeneration, that way they don't have a immediate punishment but rather a long term negative effect when ignored. Generally most effect should be more on time base and not just instant.
Having elemental spell effects do damage or otherwise affecting things in ways other than removing hitpoints would be a HUGE boost to realism, and could have many side uses. Of course, that's a whole new level of processing to determine the proximity to everything in its path or area of effect, and apply suitable changes both graphically and stat-wise.
This so much, so far you could replace EVERY attack spell with "reduce health by X", there was nothing that made one more effective or more useful than the other really.
At the one end of the spectrum, we have MW's unrealistic situation where items left lying in the middle of the street would still be lying there untouched 6 months later. At the opposite extreme, we have OB's case where everything would return to its previous state in exactly 3 days. The former case caused saved-game bloat, since EVERYTHING you affected had to be saved in memory with every save for the rest of the character's existence. The latter caused your character's very existence to be pointless, since there was never a reminder of your previous actions. Some balance needs to be struck.
Yea also the times and effects should differ depending on where the situation is. A dead body in the middle of a city will likely be gone within a day, a dead body in the wild will linger around longer but slowly get eaten by animals, could say that 2 weeks afterwards you only have a few scattered bones left. Ones in a very remote area or wasteland will likely be around for a long time but "mummifies" or fully skeletises.
Items will likely vanish quickly in towns too, in the wilderness they will probably lie around a while, natural materials would likely rot though and metals "rust" (those that can oxidize only though, no "gold rust"
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