In one of the recent patches, there is a very small but important quality of life change. Now on the Loot Box purchase screen, there is a graph that will pop up when you click the 
icon displayed just above the Loot Box purchasing options.
A few other reminders that card does not tell you.
- Contents of a Loot Box are determined when you receive that Loot Box, NOT when it is opened.
- The contents of a Loot Box are determined based on the items you have already unlocked in your collection that are available from that Loot Box and each rarity the item is. Only if you collect all possible items for a specific rarity that is available for that Loot Box will any items of that same rarity in a Loot Box could be duplicated.
- You get 50
for all Rare Coin Drops, you get 150 for all Epic Coin Drops, and you get 500 for all Legendary Coin Drops. You get 5 for all Common Duplicated Items, you get 15 for all Rare Duplicated Items, you get 50 for all Epic Duplicated Items, and you get 200 for all Legendary Duplicated Items. - You cannot earn any items from a standard loot box or an event loot box that does not appear in that Loot Box even if you have collected all possible items from that Loot Box
- You cannot earn any past promotional item or Overwatch League skins from Loot Boxes. Overwatch League skins can only be obtained with Overwatch League Tokens
and are sold separately or earned from watching eligible Overwatch League Matches. - A seasonal Loot Box is guaranteed to have at least one item from that seasonal event.
- Golden Loot Boxes will guarantee to have one Legendary ranked item but only contains items from the standard loot box distribution (no season events)
- Legendary Loot Boxes will guarantee to have Legendary ranked item and the box will pool from all seasonal events. Anniversary Legendary Loot Boxes are the same but must have at least one item that appears in Anniversary seasonal event.
