D20??

[DeadWraith]

So I've unlocked it. But what is it good for?

[Blargo]

Greed Mode.
That's basically it.

Edit: Wait, you have almost 4000 hours in this game and haven't unlocked the D20 until now?

[Mooglethyst]

https://bindingofisaacrebirth.gamepedia.com/D20

[Amelouth]

Almost 4k hours... and you still have not ended BoI???
D20 is meh to be honest but if you had breaked the game you are in for a delicacy (at least thats what I think) Try reading the link that Moogle gave you.

[beautheschmo]

Strategically, it's an ok item. It rerolls all the pickups in the room, so generally you want to use it when there's a decent number of things piled on the floor (usually after opening a chest, as empty chests also count as a pickup for the purpose of rerolling).

The main appeal of the D20 is mostly for getting extra tarot cards/runes, soul hearts and Gold Chest items, and since it scales with pickup amounts it pairs well with items that drastically increase how many pickups spawn, such as Mom's Key, Guppy's Tail (it affects the rerolled pickups as well, which makes D20 usually generate a lot more pickups) and especially Sack Head (which drop 2-3 pickups and often contain batteries, which generally allows you to loop D20 uses for long periods of time).

It has some gamebreaking potential with the right setup (D20 + Chaos + Sack Head could theoretically allow you to empty the item pool), but without synergistic items, it's not particularly impressive, most of the time you'll just get a couple of extra keys or something from rerolling worthless red hearts.

[DeadWraith]

Thank u beautheschmo. your reply was what i was looking for.