Five-star rated characters in Fire Emblem Heroes are drawn at a rate of 3.25% per summon. Suffice to say, the chances of getting a highly coveted five-star player during a summoning session is not very good.
In casinos, aside from the wild array of side bets available in craps, roulette is considered the game with the worst odds on the floor. The standard American roulette wheel has spots for 1-36, as well as a zero and a double-zero, for a total of 38 numbers for a ball to drop onto; so on every single spin, gamblers have a 2.6315789% of hitting a single number and getting a 36x payout.
The difference with roulette is that there is a variety of ways to hedge your bets, wager on half or quarter spots, mitigate losses and frustration, maximize entertainment and enjoyment, and depending on the casino, drinks are usually free and sometimes the waitresses are hot.
In FEH, you pull the slot machine, get nothing of any value, and then walk away pissed off. In less than 60 seconds. Eventually, you get back on the horse, grind your way to 20 orbs or whatever denomination one feels comfortable getting to before getting back into the casino, and the process repeats itself again and again.
As much as I’m aware of having just quoted a guy who quoted Einstein’s famous line already this week, but the definition of insanity is doing the same thing over and over again and expecting different results.