How Many Packs to Pull Greninja-GX from Forbidden Light

Greninja-GX chase methodology

This page answers exactly one question: how many Forbidden Light booster packs does it take to pull Greninja-GX #120? The numbers below come from the same per-rarity pull-rate model the PackRip Forbidden Light simulator runs on, mirrored from packGenerator.ts. TCGplayer pricing refreshes every build, so the buy-vs-rip verdict at the bottom reflects current market.

The math: ~1 in 152 per pack

Greninja-GX sits in the Full Art rare-slot pool for Forbidden Light. There are 13 Full Art cards in the Forbidden Light pool, and the Full Art slot fires with probability 8.56% per pack. Since the slot is split evenly across the 13 cards in that tier, the per-pack chance of pulling this specific card is 1 in 152 — approximately 1 in 152.

Pulls are independent and identically distributed, so the number of packs until you hit Greninja-GX follows a geometric distribution with parameter p = 0.006585. The expected number of packs is 1/p — that's ~152 packs on average. But "average" hides huge variance: the median pull lands faster than the mean (~105 packs at 50% confidence), and a long unlucky tail can stretch the wait dramatically. The 95% confidence band — 454 packs — is where 95% of pull-runs finish; the remaining 5% take even longer.

Concretely: if 100 collectors each opened Forbidden Light packs until they pulled Greninja-GX, roughly 50 of them would have it by pack 105, 95 of them would have it by pack 454, and a handful would still be chasing past that. Expected ≠ guaranteed; the geometric distribution is famously long-tailed on the right side.

Confidence bands — packs vs cumulative probability

Read this table as "what fraction of openers have pulled Greninja-GX by pack N?". A 25% band of 44 packs means a quarter of openers hit it inside that window; 99% means almost everyone has hit it by pack 698. The dollar column anchors the variance to real-world sealed-pack cost at $5/pack.

Cheaper to buy Greninja-GX as a single?

Buying Greninja-GX as a single on TCGplayer (~$56.74) is dramatically cheaper than chasing it through packs — the expected pack-rip cost is roughly $759, well above the market price.

Pack-rip expected dollar cost for this specific card: ~$759 at $5 per Forbidden Light pack. Compare to $56.74 for the single on TCGplayer (Unlimited / non-graded copy at current market). The single buy obviously delivers exactly this card; the pack-rip approach delivers Greninja-GX plus the remaining 10 cards in every pack along the way — which is why the EV calculator at /ev/sm6 spreads the cost across the whole pack contents instead of pinning it to one card.

About Greninja-GX (Forbidden Light)

Greninja-GX is a Full Art card from Forbidden Light, the 2018 Pokémon TCG expansion. Forbidden Light (2018) carries five Prism Star cards across 150 cards — Volcanion #31, Diancie #74, Arceus #96, Lysandre #110 and Beast Energy #117. Fighting is the widest type at 25. Its nine Rare Rainbows very nearly mirror the eight Rare Holo GX one for one, the exception being Lucario-GX, which appears in the Rainbow tier without a standard GX print. All six Secret Rares are Trainers or Energy.

This specific card ranks as one of the top-3 most valuable pulls in Forbidden Light by TCGplayer market value, which is part of why the chase math is what it is — high market value tends to track with rarity-tier depth, since lower pool sizes concentrate value into fewer cards. The complete top-25 Forbidden Light ranking shows where Greninja-GX sits relative to the rest of the chase pool.

Pull odds in context

For reference, a "1 in 152" pull is roughly comparable to a deep chase — multi-box territory, often case-level commitment. The variance is the killer: any one pack could be the one. The simulation on PackRip's Forbidden Light opener uses the same exact RNG model, so you can stress-test the wait curve without spending real money.

Related chases

• Diantha — Full Art, $42.12 market
• Energy Recycler — Secret Rare, $35.36 market
• All Greninja-GX printings across 4 sets
• All top-25 Forbidden Light chases
• Complete the Forbidden Light binder — full calculator

Open Forbidden Light free

Rip Forbidden Light packs free on PackRip's simulator with the same per-rarity pull rates this page is built from. The Hunt Pack mode boosts the Full Art slot if you specifically want to optimise for Greninja-GX-tier pulls. Coin economy is virtual — no real money on the line.

Strategy: optimising the Greninja-GX chase

Every experienced Forbidden Light hunter eventually picks one of three approaches for a specific chase card. The cheapest is the snipe: skip pack-ripping entirely, set a TCGplayer alert at or below the current $56.74 market, and wait for a motivated seller. This is the route most efficient-frontier collectors take when the chase is locked behind a deep rarity tier — and the math above shows why. The expected pack-rip cost ($759) is typically multiples of the single price, and the variance on that expectation is wide enough that a single bad streak can blow past the 95% confidence bound. The single buy is dollar-for-dollar cheaper and emotionally cheaper too — no more refreshing pack-pull videos at 3am.

The middle path is the box-rip-then-snipe: open a sealed booster box of Forbidden Light (typically 36 packs for vintage sets), enjoy the experience, then if you didn't hit Greninja-GX in the box, buy the single for $56.74. A 36-pack box delivers a probability of 1 − (1 − p)³⁶ ≈ 21.2% of pulling Greninja-GX at least once, where p is the per-pack hit rate of 0.006585. So a sealed box gives you roughly a 21% chance of hitting this card "for free" alongside the rest of the box contents, plus the rip experience. If you miss, you backstop by buying the single — total worst-case cost is the box price plus the single. Most rational hobbyists end here.

The expensive path is pure-rip-to-pull: keep opening packs until Greninja-GX appears. The expected total cost is ~$759, but the 95th percentile pushes that to ~$2,270. Almost nobody who does this comes out ahead financially — but it produces the binder story, the YouTube content, and the cumulative pulls of the entire pack contents along the way. If your real goal is collecting all of Forbidden Light, not just acquiring Greninja-GX, the pure-rip path has an internal logic the singles path doesn't.

Variance is the entire story

Here's a concrete illustration of how wild the geometric distribution gets at low p. Consider 10 hypothetical openers all chasing Greninja-GX from Forbidden Light. Mathematically, you'd expect their results to cluster near the 152-pack expectation — but they won't. Roughly 5 will pull Greninja-GX within the first 105 packs and feel lucky. Roughly 3 will pull between 105 and 152 packs and feel "about average". And roughly 2 will be still pulling past pack 152, with one of them potentially stretching past the 95% bound of 454. The unlucky ones will swear the simulator is rigged, the rates are wrong, or that they have terrible RNG — but the math says exactly this distribution should happen every time. The geometric distribution has no memory: each pack is an independent draw, and a 100-pack dry streak does not increase the odds of the next pack hitting.

How Greninja-GX compares to the broader Forbidden Light chase pool

Greninja-GX sits in the Full Art tier of Forbidden Light's rare-slot pool. 13 cards share this tier, and the tier itself fires roughly 8.56% of the time per pack. That means the per-pack chance of pulling any Full Art card (not just Greninja-GX) is 8.56%, which makes the expected wait for any Full Art card much shorter than the wait for this specific one. Pull-rate intuition: a single chase from a 6-card tier is 6× rarer than the tier itself. The deeper the pool, the longer the chase. This is also why "wide" sets with many chase cards in a single tier feel grindier per individual card despite the tier hit rate being identical — a thicker tier dilutes each card's specific share.

If your real goal is "any chase card from Forbidden Light" rather than "Greninja-GX specifically", the math gets dramatically friendlier — the wait drops to ~12 packs on average for the tier as a whole. Most binder collectors approach it this way: chase the tier broadly across multiple sets, accept whatever pulls, and snipe the specific holes via TCGplayer later. Targeting one card from a thick tier is the most expensive way to play the chase, and Greninja-GX is no exception.