One of the things that have always irked me about the Dark Souls games is the ability to store up souls, and effectively grind your way past a certain point by leveling up indefinitely. Accumulated failures naturally result in more souls as you go through the level again, and more souls means leveling up, thereby lessening the challenge that makes these games so great.
Is it at all possible to beat these games without leveling up at all?
Best Answer
Yes it is, there are several things in the game that make you stronger without affecting level.
Pyromancy is a spell class that levels completely based off the items and the souls you spend on enhancing it. In fact the magic adjust of pyromancy before the nerf was the highest among all spell trees even with a 50 INT Sorcerer. Currently it ranks as high as around 40 INT at max level, or possibly higher. The damage is completely independent of level and as such I have personally made a Lv15 Character with max pyromancy who has slain the four kings.
Equipment can dramatically assist in the damage a character can do. A low level character wouldn't have the endurance to wear a lot of heavy armor but further down I explain how that can be mitigated to. Even with low endurance almost any armor that is fully enhanced is extremely powerful. For weapons, the elemental weapons like Fire and Lightning do not scale at all but have fantastic base damage making them very powerful and equip-able on Lv10 characters. Even a basic longsword put to +10 Fire is extremely deadly.
In addition much equipment boosts stats, mask of child or father both provide bonuses like hp increase or weight load increase, the grass crest shield increases stamina regeneration.
Rings can mitigate a lot of the need to level. The ring of favor off of lautrec increases HP, Weight Load and Stamina by a considerable amount at the cost of never being able to take it off without destroying it. The havel ring dramatically increases weight load, the physical ring can make up for wearing a lot of light weight armor by increasing physical defense by 50-70.
The combination of all three allow you to take very low level character and make them more than strong enough to down any boss in any scenario.
Also if you mean to do it without using any souls at all, that is certainly possible as well since nearly all attacks can be dodged but it would take a considerable amount of time to do it with no souls and require absolutely no mistakes however this game is still a RPG and a no souls run would be comparable to the nsgnsncnonennenbb runs of FFX.
Finally the game still takes plenty of opportunities to kill you regardless of stats by traps and falls.