Bloodborne's defining quality is that it gives you the barest scraps of just about anything you desperately want. From level-bumping blood echoes to the barest hints about what's wrong with this place, it never feels like you get enough, which makes them feel incredibly precious.
The new Bloodborne expansion, The Old Hunters, could have upset that balance, since it aims to give you more. However, it handles these changes with a delicate touch, adding new weapons, challenging bosses, and fat droplets of lore in just the right places. While it stumbles now and again, its issues aren't enough to drown out all the good it adds, making it an expert final note on an already great experience.
An expansion in the truest sense of the word, The Old Hunters is nestled directly in the midst of the main game, opening up a new section of the world after certain mid-game conditions are met. Here you're introduced to the Hunter's Nightmare, where hunters like yourself go to kill each other when their bloodlust becomes too powerful - it's basically either Hunter Heaven or Hell, depending on your perspective.
That setup gives Bloodborne a more fulfilling heap of extra content after the main story is concluded; while the Chalice dungeons already gave you more to do in a mechanical sense, they have little to offer if lore and intrigue is the main reason you're playing. The Old Hunters, by contrast, gives you meaty bits of story to gnaw on as you explore its new zone. Now you can see into the twisted minds of the hunters you're forced to kill, and meet the legendary Ludwig, first hunter of the Healing Church and owner of the amazing Holy Blade (though he's a bit worse for wear these days). These bits of story act as satisfying rewards for taking on the intense challenges that the Hunter's Nightmare offers.
And are they ever intense challenges. In the Nightmare you're forced to face endlessly respawning hunters, enemies so ruthless and powerful that the base game does away with them after you kill them once. The Old Hunters has no such mercy, making it brutal even by Bloodborne standards, and that's before you even lay eyes on the eldritch abominations that are its bosses. Even when I was strong enough to wipe the floor with Rom the Vacuous Spider (inducer of many rage-quits in the main game) in one go, I was still struggling to bring the Nightmare's first towering, horrifically mutated boss down to half health.
That's by no means a bad thing, of course. The combat here is as fluid and smooth as ever, so as frustrating as fights can be, they never feel cheap or unfair. This increase in difficulty is perfect for fans looking for an ever-greater challenge, and the joy of besting such a ruthless opponent is as gratifying here as anywhere else in the game. Plus, you're given a brand new assortment of weapons to use against those foes, which inspire nearly child-like glee, from a hammer you can light on fire and use as an explosive, to a whirling sawblade on a stick that is legitimately my new favorite weapon. Getting to play with such fun new toys makes facing those enemies worth it, so it's not quite as bad if (and when) you get slaughtered.
Of course, players easily frustrated by difficult enemies should take heed: even if you can access the Hunter's Nightmare fairly early in the game, it's a challenge map through-and-through, so you might want to wait until you're closer to Bloodborne's final confrontation to take it on. Unfortunately, this presents a problem for players who beat the main story before accessing the DLC - because the expansion's integrated so neatly into the base game, you can't access it to the exclusion of everything else.
If you started a New Game+ file after finishing off the final boss (which the game immediately prompts you to do) then put the game down, you'll have to play the whole thing over again if you want to try out the DLC. The one drawback to an otherwise careful execution, it's a definite point of frustration for early-adopting fans, and you'll have to consider how much you love Bloodborne to figure out if it's worth it to you. On the bright side, the DLC is compatible with your standing save files, so if you happen to have a late-game save available, you'll be sitting pretty.
However, even if the bulk of the experience takes some work to reach, bits of new content sprinkled throughout the base game improve the whole Bloodborne experience greatly. In particular, Old Hunter NPCs can be summoned near boss battles, much the same way you might summon a co-op partner. Now you can call for a helping hand even if your internet connection isn't stellar, and create a stronger bond with your fellow hunters, fighting with them on more than one or two precious occasions.
There are a few issues here with faulty AI, and more than once my NPC partners got stuck on a piece of environment, forcing me to reset the section. However, this addition is by and large a strong one, and the sense of companionship brings a little warmth to this dark and awful place, however briefly. And if co-op with a real human being is more your style, the addition of the monster-slaughtering League faction improves that too, introducing leaderboards and creating an incentive to enter other people's games that didn't exist before. (Note that the NPC hunters and The League aren't exclusively part of the expansion, as all players will get access to them via a pre-release patch, but they likely wouldn't exist without The Old Hunters.)
The Old Hunters' biggest accomplishment is building up Bloodborne into an even greater version of itself. It gives us greater insight into that sick and broken world, and elicits that same feeling of intense humility when faced with a towering Lovecraftian monster. Its improvements are incremental, but stand out enough that they're easily recognizable, and bring a great deal of value to the overall experience. So while you would still have a good time playing Bloodborne without touching The Old Hunters, you'd only be hurting yourself. With that extra bit of content, Bloodborne as a whole feels bigger, fuller, and better.