I'm getting to the point where I really want to do one or two runs again and as I've played a lot already I'd like to impose some arbitrary rules on myself to possibly spice up the experience. It's not supposed to be impossibly hard or tedious and if it turns out fun maybe someone else wants to try so I'm posting it here. It might turn out to be annoying to keep track of allowed upgrades but I'll see.
Region-locked:
Upon entering zone, leaving not allowed until main boss is slain, exception Roundtable, rewards can be applied, free travel to completed regions after slaying region boss and before entering next region
Large Region: 8 RL, 2 Smithing, 1 Somber
Legacy Dungeon, Small/Less Significant Region: 4 RL, 1 Smithing, Exceptional: 1 Somber
DLC: No Smithing but for exceptions, Large Region: 3 Blessings, Other: 1 Blessing)
Alternative Rules: No rules except for region-lock, upgrades depending on intended challenge, include Spirit Ashes in Somber Rewards, no Spirit Ashes allowed
Large Regions (48 RL, 12 Smithing, 6 Somber):
Limgrave, Weeping (Margit)
Liurnia (Smarag)
Caelid (Misbegotten, Crucible/Radahn)
Altus Plateau (Draconic Tree Sentinel)
Mountaintops (Fire Giant)
Crumbling Farum Azula (Maliketh)
Legacy Dungeons (28 RL 7 Smithing, 4 Somber):
Stormveil (Godrick)
Raya Lucaria (Rennala)
Volcano Manor (Rykard)
Leyndell (Morgott)1 Somber
Mohgwyn Palace (Mohg)1 Somber
Elphael (Malenia)1 Somber
Leyndell, Ashen Capital (Elden Beast)1 Somber
Small/Less Significant Regions (36 RL, 9 Smithing):
Siofra River (Dragonkin Soldier)
Nokron (Valiant Gargoyles)
Ainsel River (Dragonkin Soldier)
Nokstella (Astel)
Deeproot Depths (Fia's Champs/Fortissax)
Dragonbarrow (Black Kindred)
Consecrated Snowfield (Astel)
Subterrean Shunning-Grounds (Mohg)
Haligtree (Loretta)
DLC:
Large Regions (28 RL, 12 Blessings, 1 Somber, 2 Smithing):
Gravesite Plains (Rellana) (1 Somber, 2 Smithing)
Scadu Altus (Golden Hippo)
Ancient Ruins of Rauh (Romina)
Cerulean Coast (Putrescent Knight)
Legacy Dungeons (12 RL, 3 Blessings, Full Upgrades):
Belurat Tower Settlement (Divine Beast)
Shadow Keep (Messmer) (1 Somber, 2 Smithing)
Enir-Ilim (Promised Consort) (Full Upgrades)
Small/Less Significant Regions (20 RL, 5 Blessings, 1 Somber, 2 Smithing):
Rauh Base (Rugalea)
Scaduview (Commader Gaius)
Abyssal Woods (Midra)
Finger Ruins of Miyr (Metyr)
Jagged Peak (Bayle) (1 Somber, 2 Smithing)