How we set the chances

This page explains the reasoning. The actual numbers live on pack tiers, because they are read from the engine's configuration rather than written down here.

Every pack has a floor

Most slots in a pack are fixed: a slot named for a rarity always produces a card of at least that rarity. Add those base slots up and you get a hard minimum value for the pack — a number you cannot land below, however badly the chase slot rolls.

That floor is the honest thing to judge a tier by. "Expected value" is an average across thousands of packs; the floor is a promise about your pack.

The floor and the chase are zero-sum

Here is the trade-off, and it is not a matter of generosity:

At a fixed price, every dollar locked into a guaranteed base slab is a dollar the chase slot cannot climb with.

Raise a tier's floor and its top-end chances necessarily fall. Improve the chance of a headline card and the floor necessarily drops. There is no configuration that improves both, because there is no spare money in the pack to improve them with.

This is why the line-up has more than one tier. Different buyers want different points on that curve — some want to be protected against a bust, others want the longest possible reach — and one product cannot be both.

Variance is paid for out of the floor

The same trade-off explains why the cheapest tier is not simply "the same pack, smaller". A low-priced single-card pack is the harshest product we could build: with only one slot there is nothing to soften a bust, so the floor has to carry the whole downside. Pricing a tier higher is often what makes a better floor affordable, not just a bigger chase.

Two different rolls, one after the other

Each slot in your pack resolves in two steps, and they answer different questions:

1. Which rung does this slot land on? A roll against the slot's published tier table. This is the step the published chances describe, and the one you can verify afterwards. It depends only on the two seeds and the table — never on what is in the vault.
2. Which specific slab from that rung? A second roll, weighted so the rung pays out what it is supposed to pay out on average, across the cards actually in stock at that rung.

Keeping these separate is what stops stock levels from bending the chances. A rung running low changes which slab you might get, never how likely you are to reach that rung.

Both rolls happen before the pack is opened, so opening it is a reveal, not a draw.

What this page does not cover

The exact floor, expected value and per-rung chance for each tier are published in the app and on pack tiers, driven by live configuration. If a tier is retuned, those update; this page does not need to, because it only describes the shape of the trade-off.