In the previous test, I measured all 30 packs from a Japanese Inferno X booster box and compared pack weight with SR, AR, RR, and R results.
This time, I tested MEGA Dream ex.
MEGA Dream ex is a Japanese High Class Pack product with 10 cards in each booster pack, making it very different from the standard five-card Japanese expansions I tested previously.
The set also introduced a new rarity called MA, or Mega Attack Rare, and includes several types of Mirror Holofoil cards.
For this experiment, I used all 10 packs from an unopened booster box that I purchased myself.
Every sealed pack was weighed individually to the nearest 0.01g. I then opened all 10 packs and recorded the relationship between pack weight and MA, SR, AR, and RR results.
The overall result showed an interesting tendency.
The three heaviest packs in this booster box all contained either an SR or an AR.
However, packs with identical displayed weights also produced different results.
At 16.37g, one pack contained an AR in addition to an RR, while another contained only an RR.
At 16.40g, one pack contained an MA, while another pack at exactly the same displayed weight contained only an RR.
Therefore:
Although the heavier packs in this booster box were more likely to contain an additional higher-rarity card, pack weight alone could not accurately identify what was inside an unopened pack.
This article documents an experiment into whether what is commonly known as “pack weighing” can actually distinguish card rarity.
It is not intended to encourage weighing packs in stores, selecting packs by weight before purchase, or selling packs that have been sorted by weight.
Pack weight may also be affected by the foil wrapper, printing, card finishes, Mirror Holofoil treatments, manufacturing variation, humidity, the measuring environment, and scale accuracy.
The measurements shown here apply only to this specific booster box.
They should not be treated as universal standards for other booster boxes, production batches, or loose packs.
What Is Different About MEGA Dream ex?
MEGA Dream ex is a Japanese High Class Pack product containing 10 cards per booster pack.
This makes each pack significantly heavier than the standard five-card Japanese expansion packs tested elsewhere in this series.
The set also introduced the MA, or Mega Attack Rare, rarity.
In addition to MA, the product contains rarities such as AR, SR, and SAR, as well as several types of Mirror Holofoil cards.
Because both the number of cards and the types of surface treatments differ from standard booster packs, there are more variables that may affect the final weight of each sealed pack.
Test Conditions
The test was conducted under the following conditions.
- Product: Japanese MEGA Dream ex High Class Pack
- Purchase format: unopened booster box
- Number of packs measured: 10
- Cards per pack: 10
- Every pack was weighed while sealed
- Measurement precision: 0.01g
- Location: normal indoor environment
- All 10 packs were opened after weighing
- MA, SR, AR, and RR results were recorded
MEGA Dream ex contains multiple types of Mirror Holofoil cards.
This means that differences in total pack weight may not be caused only by higher-rarity cards.
The foil wrapper, printing coverage, surface treatments, the type and number of Mirror Holofoil cards, and other manufacturing differences may all affect the final measurement.
For this reason, the measurements below should be viewed as relative data comparing the 10 packs within this specific booster box, not as absolute rarity thresholds.
MEGA Dream ex Pack Weight Results: 10 Packs Measured
The 10 unopened packs measured in this test ranged from 16.34g to 16.50g.
The average weight was approximately 16.41g.
The difference between the lightest and heaviest packs was 0.16g.
| Measurement | Weight |
|---|---|
| Lightest pack | 16.34g |
| Heaviest pack | 16.50g |
| Average of all 10 packs | Approx. 16.41g |
| Difference between lightest and heaviest | 0.16g |
However, identical displayed weights did not always produce identical results.
At 16.37g, one pack contained an AR and RR, while another contained only an RR.
At 16.40g, one pack contained an MA with no RR observed, while another contained only an RR.
Therefore, this test did not reveal any clear weight threshold where a specific rarity could be reliably identified.
Measured range: 16.34g–16.50g
Average pack weight: approximately 16.41g
Difference between lightest and heaviest pack: 0.16g
RR cards were observed in nine of the 10 packs.
Four of those packs also contained either an SR or an AR.
One 16.40g pack contained an MA, and no RR was observed in that pack.
The remaining five packs contained only an RR among the rarities tracked in this test.
What the Measurements Showed
The main findings from these 10 packs were:
- The three heaviest packs, weighing 16.46g or more, contained either an SR or an AR
- The 16.50g and 16.48g packs contained AR cards
- The SR appeared at 16.46g, the third-heaviest pack in the box
- The MA appeared at 16.40g
- At 16.40g, one pack contained an MA while another contained only an RR
- At 16.37g, one pack contained an AR and RR while another contained only an RR
- Nine of the 10 packs contained an RR
- The 16.40g MA pack was the only pack in which an RR was not observed
The five packs containing an MA, SR, or AR had an average weight of approximately 16.44g.
The five packs containing only an RR had an average weight of 16.37g.
That is an average difference of approximately 0.07g.
Within this booster box, packs containing MA, SR, or AR therefore tended to be heavier on average.
However, the identical-weight results at 16.37g and 16.40g show why averages cannot be used to identify individual unopened packs.
SR Pack Weight
The SR observed in this booster box came from a pack weighing 16.46g.
This was the third-heaviest pack among the 10 measured.
The result shows that the SR appeared toward the heavier end of the distribution.
However, the two packs that weighed even more—16.48g and 16.50g—contained AR cards instead.
This means that increasing pack weight did not correspond directly to increasing card rarity.
The only conclusion supported by this test is:
In this booster box, the SR was found in a relatively heavy 16.46g pack.
This does not mean that packs above a particular weight contain an SR or that the heaviest pack will contain an SR.
MA Pack Weight
The MA observed in this booster box came from a pack weighing 16.40g.
MA, or Mega Attack Rare, was introduced with MEGA Dream ex.
However, the MA pack was not among the heaviest packs in this booster box.
It appeared closer to the middle of the overall weight distribution.
More importantly, another pack also weighed exactly 16.40g and contained only an RR.
- 16.40g: MA
- 16.40g: RR only
Based on these results, the MA could not be identified using pack weight alone.
Even if the MA card's surface treatment affected its weight, that difference may have been offset by variations in the other cards, Mirror Holofoil treatments, or packaging.
AR Pack Weight
The AR cards observed in this booster box appeared at:
- 16.37g
- 16.48g
- 16.50g
Their average pack weight was approximately 16.45g.
The 16.48g and 16.50g AR packs were the two heaviest packs in the entire booster box.
However, another AR appeared much lower at 16.37g.
A second pack weighing exactly 16.37g contained only an RR.
- 16.37g: AR + RR
- 16.37g: RR only
This means AR cards appeared both at the very heavy end and closer to the lighter half of the distribution.
Therefore, an AR may appear in a heavy pack, but AR packs cannot be assumed to always be heavy.
RR-Only Pack Weights
The five packs that contained an RR without an MA, SR, or AR weighed:
- 16.34g
- 16.36g
- 16.37g
- 16.38g
- 16.40g
Their average weight was 16.37g.
Overall, these packs were concentrated toward the lighter end of the distribution.
The 16.34g and 16.36g packs were the two lightest packs in the booster box, and both contained only an RR among the rarities tracked here.
However, an AR also appeared at 16.37g, while the MA appeared at 16.40g.
This means there was no clear weight boundary below which every pack could be identified as RR-only.
The Three Heaviest Packs Contained SR or AR
One of the most noticeable results from this booster box involved the three heaviest packs.
- 16.50g: AR + RR
- 16.48g: AR + RR
- 16.46g: SR + RR
All three contained either an SR or AR in addition to an RR.
Within these 10 packs, this suggests that the heavier end of the distribution was associated with additional rarities.
However, the MA appeared at only 16.40g, and another AR appeared at 16.37g.
Therefore, not every pack containing an additional rarity was located at the heaviest end of the booster box.
The Same Weight Produced Different Results
This was one of the most important findings from the experiment.
Two different measurements produced different opening results despite showing exactly the same weight on the scale.
- 16.37g: AR + RR / RR only
- 16.40g: MA / RR only
Even when measuring to the nearest 0.01g, there was no way to distinguish these packs before opening.
MEGA Dream ex also contains multiple types of surface treatment and Mirror Holofoil cards.
The weight added by a higher-rarity card may overlap with variations caused by the other cards or the foil wrapper.
Mirror Holofoil patterns and quantities were not individually classified in this test, so the exact contribution of each factor cannot be isolated from this dataset.
Results by Weight Range
The opening results from this booster box can be grouped into several approximate weight ranges.
✅16.46g–16.50g: SR or AR observed
All three packs in this range contained either an SR or an AR.
However, this observation applies only to this specific booster box and should not be treated as a guaranteed high-rarity weight range.
✅Around 16.40g: MA and RR-only results overlapped
One 16.40g pack contained an MA.
Another 16.40g pack contained only an RR.
The identical displayed weight produced different results.
✅16.37g–16.38g: AR and RR-only results overlapped
At 16.37g, both an AR + RR pack and an RR-only pack were observed.
There was therefore no clear boundary separating the two.
✅16.34g–16.36g: RR only in this booster box
The packs observed within this range contained only an RR among the rarities tracked in this test.
However, only two packs fell within this range.
The result should not be assumed to apply to other booster boxes.
No packs in this booster box measured 16.39g or between 16.41g and 16.45g.
Because there is no data for those measurements, no conclusion can currently be drawn about those weight ranges.
Can Japanese MEGA Dream ex Packs Be Weighed to Identify Rarity?
The three heaviest packs in this booster box all contained either an SR or an AR.
The five packs containing an MA, SR, or AR were also approximately 0.07g heavier on average than the five RR-only packs.
However, the full dataset also showed:
- An AR + RR pack and an RR-only pack both weighed 16.37g
- An MA pack and an RR-only pack both weighed 16.40g
- AR cards ranged widely from 16.37g to 16.50g
- The MA appeared at 16.40g rather than at the heaviest end
- Mirror Holofoil cards and packaging introduce additional weight variables
Based on these results, heavier packs showed some tendency to contain additional rarities within this booster box, but pack weight alone could not accurately distinguish MA, SR, AR, and RR results.
The measurements published here should be viewed as data collected after fully opening one booster box, not as weight thresholds for selecting “hit packs.”
Summary of the MEGA Dream ex Pack Weight Test
After measuring and opening all 10 Japanese MEGA Dream ex packs, the main results were:
- The overall measured range was 16.34g–16.50g
- The average pack weight was approximately 16.41g
- The three heaviest packs contained either an SR or an AR
- The SR appeared at 16.46g
- The MA appeared at 16.40g
- AR cards appeared at 16.37g, 16.48g, and 16.50g
- An AR + RR pack and an RR-only pack both appeared at 16.37g
- An MA pack and an RR-only pack both appeared at 16.40g
- Pack weight alone could not accurately identify rarity
The heavier end of this booster box did contain several additional higher-rarity cards.
However, the MA and one AR appeared at much lower weights, while identical displayed weights also produced different opening results.
This makes MEGA Dream ex a useful example of why pack-weight averages and overall tendencies should not be treated as reliable thresholds for individual packs.
This is the eighth pack-weight dataset published on the English version of tekemero.com.
Future tests will continue comparing Japanese products under similar measuring conditions.
For MEGA Dream ex in particular, measuring additional booster boxes and recording the type and number of Mirror Holofoil cards may help show which variables contribute most to the overall pack-weight differences.
