Gamers believe it has to be someone who's been to these stores, and plays the game quite often.
Store owners worry the thieves may strike again...
Magic: The Gathering has been around since 1993.
Cards average $10-15 each now...
But some of the cards issued back then are now worth $3,000 - $4,000.
So, it's easy to see why someone would want to steal them.
"They know what they are taking. They targeted the expensive cards and they were in and out in less than a minute."
Mike Pazin owns The Bullpen, and believes the culprit is someone who knows the game, and its value.
"The most expensive card is a black lotus that came out in 1993. It was in 2 different sets. The value right now is about $3000 for that card."
...and that's the same amount he lost in Magic cards.
At Pazin's store, security video shows the thieves throwing rocks at the glass then busting through.
Over at the Crazy Squirrel, Jennifer Ward says thieves used a pellet gun to break the glass.
"It doesn't completely break, so then he puts his shoulder into it 5 or 6 times and busts the window. Comes right across, goes directly to where we kept our magic cards at the time."
That was on Monday, November 26th.
$4,000 worth of Magic cards was stolen that night, causing a couple thousand in damage.
Thieves came back like "ravenous demons" this past Monday... But ran like... well, you know... after the lights came on.
So what's the appeal?
Gamers say the cards are untraceable... So you can't track them back to any one store.
But the potential to make more money, based on the cards you have, is huge.
While local tournaments will pay out a few hundred dollars... Level 2 Magic judge Tyler Morrison says the larger scale games reward thousands.
"It goes from people that just play casually at home with friends, up to people that are playing this game professionally, and supporting themselves and their families just by playing this game."
Store owners say the gaming community is very close-knit...
Some of these guys are so upset about the burglaries, they're actually waiting outside the stores until 3:00 a.m., to make sure the thieves don't come back for another "gathering."
No word on any arrests by Fresno Police.
The investigation is ongoing.