My hard-core mode wish list.
Drugs, Alcohol and Pain in Hard-core Mode.
Pain
I would like to see a pain effect in hard-core mode when you are badly injured. The pain effect could be done by muffling sounds and have the screen peripherals going in and out of focus, like a throbbing tunnel vision (the tunnel is blurry not black) with the tunnel restricting like a heartbeat (no heartbeat sound that would be too much). Pain would be abated by using Med-X, some sort of homemade pain killer, being healed for a while (taking a bunch of Stimpaks will not make the pain go away instantly) or having a busted limb fixed.
Perception should also be reduced during pain.
I would also give Stimpaks (and other strong healing chemicals) a pain effect while they are active. These would be some serious chemicals you are injecting into your body, they are likely to hurt a bit.
No instantly healed limbs in Hard-core Mode.
Strong medication or a doctor with both requiring rest (eight hours). Med-X could help with movement until the limb is healed.
Alcohol
In real life you have a reason to drink alcohol (mostly to get a bit silly) but in the Fallout series there was no reason and especially FO3 and NV it was just a p1ss poor strength potion. In the Witcher series you could have drinking contests to get information and loot and there are even “quests” where Geralt gets drunk at parties.
How about the protagonist is able to let their hair down get drunk (make getting drunk funny) and wake up with a ghoul. Maybe having a temporary perks like De-stressed that lasts for a few game weeks and Hung-over for a few games hours the next morning.
While drunk the screen goes slightly out of focus now and then and triggers strange dialog options with some NPC’s, and may open up information dialog with other drunk NPC’s like pass words and hidden entrances to areas.
When the PC drinks more than their Endurance can handle the PC blacks out, loses several hours, maybe waking up with missing caps and / or in a strange location.
Drugs
Excess drugs could have a wide range of effects like having a companion look like a super mutant or the deathclaw, have everyone appear hostile on the Friend/Foe Markers in the Compass and any other weirdness. Similar effects could also occur during withdrawal.
Trapping
I would like to see a trapping mechanic added to the game tied to the Survival Skill. You’re not going hunt small animals to eat but you could trap them. Set a snare somewhere come in back after several hours and see what you have caught.
Fresh food going off
If it could be done practically I would like to see fresh food go off unless your character does something to preserve the food. Off meat would make a good lure for a trap. Also eating pre-war food could randomly make you sick when you get a bad one. Also more than one or two pieces of meat off large animals.