The recurring operations event. Thirteen atomic skills, three tiers of intensity, one weekend a month. Show up, run the operations, walk away sharper.
Core 13 is AtomicCTF's recurring event format. Thirteen operations drawn from across the atomic skill graph — encoding, exploitation, lateral movement, detection, IR — playable solo or as a small team, gated by tier.
Different operations every month. Some Ground-Zero-friendly, some intermediate, some genuinely tough. The point isn't to crush you — it's to give you thirteen real reps against techniques you'll encounter on a real engagement.
Entry tier. The thirteen operations, beginner-friendly. Generous hints, no leaderboard pressure. Built for first-time players and Ground Zero graduates.
The standard tier. Same thirteen operations, scaled up — fewer hints, tighter scope, ranking enabled. Most operators run Fusion.
The hard tier. Hints withheld, time-boxed, full leaderboard. For operators who already know the technique and want to see how clean they can run it.
One-off CTFs are great spectacles. They aren't great training. The skill comes from seeing the same shape of problem in a slightly different costume, again and again, until it becomes second nature.
Core 13 runs monthly. Some operations rotate. Some recur intentionally — the same kind of decode, the same kind of pivot, the same kind of detection — because that's how a real operator builds intuition.
If you show up to twelve Core 13 events in a year, you've run roughly 156 atomic operations under time pressure. That's a serious year of training, regardless of what your day job looks like.