NHF – new heroes for Heroes V 3.1.

It's not entirely important, although it's probably true. The main thing is the principle. It's important. Ghosts are just an example to understand the essence.

For some, auto-hit on 3 and auto-hit on 4 are different. In one case, stability is higher, and in the other, it's lower. Therefore, when implementing a system that emphasizes stability, the first option is better, especially since the ghost mechanic is familiar to many.

Added 5 minutes later
Although the chance is 30%, not 50%, so the situation is different. Then I suggest this: after 6 misses in a row, the seventh hit is guaranteed, and after any hit, the next shot is guaranteed to miss. This is balanced and almost doesn't change the 30% chance. Plus, it's the most stable of the possible options.

Added 3 minutes later
Simple calculation: 6 misses in a row have a probability of about 12% (0.7^6). In this case, the probability of the 7th hit increases from 30 to 100%, i.e., +70% in 12% of cases. On the other hand, the chance of a regular hit is 30%, after which the chance of hitting on the next attempt decreases from 30 to 0, i.e., -30%. In total, +0.7x0.12 - 0.3x0.3, which is approximately zero.