If you’re staring at a bunch of maxed B-rank Blood Codes and wondering why the game refuses to hand over A or S ranks, don’t worry — you didn’t mess anything up. This is one of those Code Vein systems that’s way less obvious than it should be, and a lot of players hit this same wall.
Let’s break down why your Blood Codes aren’t upgrading, what actually unlocks A and S Blood Codes in Code Vein, and when you can realistically expect them to show up.
First, A-rank and S-rank Blood Codes are not unlocked by affinity alone. Even if your B-rank Blood Codes are fully mastered and your affinity with companions is high, the game won’t upgrade them early. Code Vein ties higher Blood Code ranks directly to story progression and area difficulty.
Second, enemy level matters more than most players realize. If you’re fighting weaker enemies in earlier areas, Blood Code progression effectively stops. To unlock A Blood Codes, you need to push into later zones with stronger enemies and keep using the Blood Codes you want to upgrade.
Finally, S Blood Codes are mostly endgame rewards. Many players only receive them after major story milestones or the final boss. Once you hit those points, go back and talk to NPCs again — they’ll hand over the A or S Blood Codes automatically when the requirements are met.
The Short Version (So You Don’t Waste Time)
Maxing B-rank Blood Codes and raising affinity isn’t enough on its own. Even if everything looks fully upgraded, Code Vein won’t unlock higher tiers early.
A-rank Blood Codes — and especially S-rank Blood Codes — are locked behind story progression and late-game enemy scaling. The game expects you to move forward, reach tougher areas, and fight stronger enemies before those upgrades become available.
If you’re still around Prison Island, you’re simply too early. At that point in Code Vein, A and S Blood Codes aren’t meant to unlock yet, no matter how much you grind or how high your affinity is.
Why Your Blood Codes Are “Stuck” at B Rank
You’re Not Far Enough in the Story
This is the biggest reason most players get stuck.
If you’re at Prison Island, the game still considers you to be in the mid-game. Even if everything else looks perfect — the upgrades simply aren’t meant to happen yet.
This applies even when:
- Your B-rank Blood Codes are fully mastered
- You’ve raised affinity with characters like Lou, Noah, or Lyle
- You keep swapping partners and rechecking NPC dialogue
None of that will force the next tier to unlock early. A-rank Blood Codes only start appearing in later story zones, once you’ve pushed past Prison Island and hit more advanced areas. Until then, B rank is the intended cap, no matter how much you grind.
Enemy Level Matters More Than You Think
Blood Code progression quietly stops if the enemies you’re fighting are too weak for your current level. The game doesn’t warn you when this happens, which is why it can feel confusing or even bugged.
If you’re farming earlier areas:
- Blood Code proficiency won’t increase
- Upgrade checks for A or S ranks won’t trigger
- It looks like something is broken (but it isn’t)
To keep progressing your Blood Codes, you need to move into later zones with stronger enemies. Once you’re fighting appropriately scaled, late-game enemies again, Blood Code progression resumes naturally and higher-rank upgrades can finally unlock.
NPCs Only Hand Out Upgrades After Story Flags
NPCs won’t upgrade your Blood Codes the moment you meet the requirements. Even if your B-rank Blood Codes are maxed and you’re technically eligible, the game won’t hand anything over until certain story flags are triggered.
What you need to do is:
- Progress the main story
- Trigger new story dialogue or cutscenes
- Leave and come back, then talk to the NPC again
If you speak to them too early, they’ll have nothing new to say — even if all other conditions are met. Once the correct story milestone is reached, the upgrade happens automatically the next time you talk to them.
S-Rank Blood Codes Are Endgame Content
This is the part that catches a lot of players off guard.
Based on community testing and shared experiences, S-rank Blood Codes in Code Vein are not mid-game unlocks. They’re intentionally held back until very late in the story.
Here’s how it generally works:
- A-rank Blood Codes begin unlocking in the late game
- S-rank Blood Codes are mostly endgame or post–final boss rewards
- Some S-ranks only appear when you reach the route leading to the second ending
If you haven’t reached those story points yet, there’s nothing you’re missing or doing wrong. You physically can’t get S-rank Blood Codes early — the game simply isn’t ready to give them to you.
How to get A-S codes? (Step-by-Step)
If you want to unlock A and S Blood Codes as soon as possible, this is the safest and most efficient approach to follow. Doing these steps in order will save you a lot of wasted time and confusion.
- Finish maxing out your B-rank Blood Codes
- Push the main story past Prison Island
- Move into late-game areas with tougher enemies
- Keep the Blood Code you want equipped while fighting there
- Swap partners occasionally, as this can help trigger upgrade checks
- Defeat major story bosses as you progress
- Return and talk to NPCs like Lou, Noah, and Lyle
- For S-rank Blood Codes, reach the endgame or defeat the final boss
- After each major story beat, talk to everyone again
Once all the requirements are met, NPCs will automatically hand over the upgraded A or S Blood Codes. There’s no extra quest or hidden trick — just progression and timing.
Common Questions Players Ask
Do I need max affinity to unlock A or S Blood Codes?
No. Affinity helps with NPC interactions, but story progression and enemy level matter far more when it comes to unlocking A-rank and S-rank Blood Codes.
Can I grind early enemies to force upgrades?
No. Farming low-level enemies won’t push your Blood Codes forward. Higher-rank progression only counts against stronger, late-game enemies.
Can I miss A or S Blood Codes?
No. A and S Blood Codes are not missable. Once you reach the correct story point, you can always return and unlock them later.
Does swapping partners actually matter?
Swapping partners doesn’t unlock Blood Codes by itself, but many players report it helps trigger NPC upgrade checks once you’ve met the story requirements.
Final Take
If you’re stuck at B-rank Blood Codes around Prison Island, you’re exactly where the game expects you to be. Nothing is broken, and you haven’t missed anything important.
Keep playing.
Push into late-game zones.
Then come back and talk to everyone again after major story moments.
That’s when the upgrades start happening.
A-rank Blood Codes unlock later in the story.
S-rank Blood Codes are endgame rewards.
It might not be clearly explained, but that progression is intentional.
It’s not bad design — it’s just very Code Vein.