The two official numbers
- 0.045%: EA's disclosed Heirloom Shards probability when opening an Apex Pack.
- 500 eligible packs: the maximum EA says an eligible player can open without receiving Bonus Heirloom Shards.
The guarantee does not mean each pack has a 1-in-500 rate. It is a separate ceiling applied after repeated eligible packs.
Cumulative lower-bound estimates
For n < 500, LootCalc uses 1 - (1 - 0.00045)^n. The table below is generated from the same executable model as the calculator.
| Eligible packs | Cumulative estimate | Maximum remaining |
|---|---|---|
| 1 | 0.045% | 499 |
| 50 | 2.225% | 450 |
| 100 | 4.401% | 400 |
| 250 | 10.643% | 250 |
| 499 | 20.116% | 1 |
At 499 eligible packs, the simplified lower-bound estimate is about 20.12%. The complementary percentage is not an EA-published player statistic; it is only the mathematical complement of this fixed-rate model. At 500, the tool stops reporting probability and shows a guarantee diagnostic.
Which packs count?
EA's FAQ excludes Collection Event, Thematic Event, Milestone Event, Collection Retro, and packs that may provide replacement items. A reward coming from a Battle Pass, level, promotion, or store is not enough information by itself: identify the actual pack type before counting it.
Eligibility can pause
EA says a player who owns all available Base Mythic items, or already has enough Shards to acquire every unowned Base Mythic item, may be ineligible for the Bonus Shards guarantee. Packs opened during that period do not advance the counter. This is one reason a self-tracked total can disagree with the hidden account state.
What the public data does not support
- No published PC-versus-console Heirloom rate difference.
- No published temporary modifier that should be added to the Heirloom rate.
- No public API that lets LootCalc read your account's hidden guarantee counter.
- No safe way to infer completed guarantee cycles from a lifetime pack total using division or modulo.