What a Blood token is
A Blood token is a colorless artifact with a single ability:
{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.
Blood arrived in Innistrad: Crimson Vow in 2021, fitting the vampire theme, and has appeared periodically since.
The card math, honestly
Count the cards through a full Blood activation.
You start with the Blood on the battlefield and some number of cards in hand. You pay one mana, tap the Blood, discard a card from hand, sacrifice the Blood, and draw a card.
Hand size: unchanged. Permanents: one fewer. Mana: one fewer.
So a Blood token, used, costs you one mana and one permanent to swap one card for another. In raw card economy terms you are down a card compared to never having had it, because the Blood itself was a thing you had and no longer do.
This is why calling Blood card draw is wrong. It is card selection. You trade your worst card for an unknown card, which is valuable when your worst card is genuinely dead and much less valuable when your hand is already good.
Compare to a Clue token, which costs two mana and sacrifices itself to draw a card with no discard. That is genuine card advantage: hand size goes up. Blood is cheaper and does less.
Why the discard is the point
Here is the reframe that makes Blood good.
Stop thinking of Blood as a way to draw a card. Think of it as a one mana discard outlet that replaces itself.
Discard outlets are a genuinely scarce resource. A large number of strategies want a specific card in the graveyard rather than in hand, and getting it there is normally awkward:
Reanimator wants a huge creature in the graveyard so it can be returned cheaply. Drawing that creature is a problem, not a solution, until you can discard it.
Madness wants cards discarded specifically, because madness lets you cast them from the discard for a reduced cost. A discard outlet turns madness cards from a liability into a discount.
Threshold, delirium, and graveyard count payoffs want card types and raw card count in the yard.
Escape and flashback cards actively want to be in the graveyard, where they are castable.
For any of those decks, the draw attached to Blood is the bonus and the discard is the reason you are playing it. A one mana, repeatable-if-you-make-more, self-replacing discard outlet is a strong effect, and it costs you almost nothing because the card you lose is replaced.
The cost timing detail
The discard is part of the activation cost, not the effect. This has three consequences worth internalising:
You discard before you draw. You cannot see the new card and then decide what to pitch. Pick your discard blind.
The discarded card hits the graveyard immediately, before the draw resolves. So if you have a payoff that triggers on a card hitting your graveyard, that trigger goes on the stack above the draw.
Once paid, it cannot be undone. Destroying the Blood in response does nothing, because the Blood is already sacrificed as part of the cost.
Blood versus the other artifact tokens
| Token | Cost to use | Effect | What it really is |
|---|---|---|---|
| Treasure | Tap, sacrifice | One mana of any color | Ramp and fixing. The best of the four. |
| Clue | Two, sacrifice | Draw a card | Real card advantage. |
| Blood | One, tap, discard, sacrifice | Draw a card | Filtering and a discard outlet. |
| Food | Two, tap, sacrifice | Gain three life | A body for sacrifice decks. |
Blood sits in a specific niche: it is the cheapest of the four to activate at one mana, and the only one whose cost includes a card. Whether that cost is real depends entirely on whether your deck wants the discard.
In a deck with no graveyard synergy, Blood is a mediocre filtering effect. In a graveyard deck, it is close to free value.
Which decks want Blood
Strongly want it: reanimator, madness, any deck with escape or flashback cards, delirium and threshold decks, anything counting cards in the graveyard.
Mildly want it: artifact synergy decks, which get a free artifact regardless of whether they use it, and sacrifice decks that want fodder.
Do not want it: decks that need raw card count rather than selection. If your problem is running out of cards, Blood does not fix it. You want Clues, or actual draw spells.
Rules notes
No summoning sickness. Artifacts are not creatures. Tap it the turn it arrives.
The artifact type matters. Like Food, Blood counts for artifact synergies while it sits there, which is a small ongoing benefit for doing nothing.
Blood is a subtype. The type line is Artifact, with Blood as the subtype, so artifact removal handles it and it counts as an artifact everywhere.
Doubling works. Any effect that doubles token creation makes two Bloods, which turns a single filter into a genuine dig two.