Blood Donor

BLOOD DONOR
large number (8+)
sticky notes

queue people up. on each sticky note, write sequential opposite numbers (+1, -1, +2, etc.) and stick to player’s foreheads. those are their “blood types”.

call out a criteria the sum of their numbers must meet. players try to find partner they meet that criteria with (e.g. “even number”, -1 and +1 pair, -1 and +2 don’t). when they do, they lock elbows. after too long without partner, eliminated. repeat. not always possible.

possible criteria:
- negative sum
- positive sum
- even sum
- odd sum
- prime sum
- composite sum