I sometimes have fun at drafts, like when I actually get a half-decent deck, and at one point I played a bunch of these "mini-decks" with some friends outside of drafts and it was actually kind of fun.
The rules more or less correspond to what you can get in a draft, all cards must be from only 3 sets of a given block with sets being from 4th edition or above or, 2 sets of one block and a core-set that was in standard-format with any set of a single block, i.e. any core set that was released just before or just after a particular block. There also number limitations,
5 cards of one type of common, but you may not have 4 of another common, you can only have 2 cards each of two types of common and the value of the 5-card common must not exceed $2.00
4 cards of one type of common, but you may only have 2 cards each of 2 types of commons.
2 cards each of three types of common
1 card each of every other common except for basic lands
2 cards each of two types of uncommon
1 card of one type of another uncommon
2 of up to one type of rare or 1 card of two types of rares.
1 of another type of rare
If you have 3 rares, you may not have a mythic rare
1 of one type of mythic rare, but you may not have more than 1 card each of two types of rares
The rules more or less correspond to what you can get in a draft, all cards must be from only 3 sets of a given block with sets being from 4th edition or above or, 2 sets of one block and a core-set that was in standard-format with any set of a single block, i.e. any core set that was released just before or just after a particular block. There also number limitations,
5 cards of one type of common, but you may not have 4 of another common, you can only have 2 cards each of two types of common and the value of the 5-card common must not exceed $2.00
4 cards of one type of common, but you may only have 2 cards each of 2 types of commons.
2 cards each of three types of common
1 card each of every other common except for basic lands
2 cards each of two types of uncommon
1 card of one type of another uncommon
2 of up to one type of rare or 1 card of two types of rares.
1 of another type of rare
If you have 3 rares, you may not have a mythic rare
1 of one type of mythic rare, but you may not have more than 1 card each of two types of rares
Any number of basic lands
Like this from a really good block I remember
3 Glistener Elf
2 Virulent Wound
1 Unnatural Predation
2 Mutagenic Growth
2 Dismember
2 Contagion Clasp
1 Darksteel Axe
1 Fume Spitter
2 Putrefax
1 Skithiryx, the Blight Dragon
1 Instill Infection
5 Forest