How do trading card companies (TOPPS, Pokémon, MTG, etc.) fairly distribute rare cards across all the manufactured packages?
Trading cards like these are printed on large uncut sheets, with usually more than 100 cards to a single sheet. There are multiple different sheets for any given set, usually separated by rarity.
This way when the cards all get cut out of the sheet, the packager is able to control how many cards of each rarity will end up in a single pack together while still being somewhat random.
The cards aren’t printed individually, they’re printed on massive sheets then cut and packed. So on each sheet they’ll change up the rare slot during printing but not the land/common/uncommon slots so different rares/mythics get mixed in. This is how % can remain constant.
Depends on what you mean. MtG, at least, has “slots” so that each pack of 15 cards has 10 common cards, 3 uncommon cards, 1 basic land, and 1 rare. This way, every pack has at least a rare, and that rare slot has a chance of being a mythic rare, and one of the common slots has a chance of being a foil version of any rarity. These slots can be adjusted, depending on the set.
If you mean how they distribute rare card X, which is worth $1, vs rare card Y, which is worth $150, then they kinda… don’t. It’s all random, but there are always trends. You’ll see people buying the same packs from more than one area so they get a “fair” shake at getting the good stuff.
The cards are cut apart and then stacks of cards (sometimes random and some times in a set order) are inserted into a collator. Each tower of the collator can hold whatever cards you want and can be programmed as to when to drop a card into a pack. So you can have a several towers of regular cards and one tower of rare cards. If a pack is supposed to have 7 regular cards and 1 rare card you would have 8 towers of cards and the pack would pass under each tower and get one card. Video shows a pretty good sample. Skip to around 1:10 to see collator.
The answer is they don’t. That’s why collectors buy boxes of card packs from all over the country to find said rate cards.