World of Warships: Legends

Just to clear any confusion you do not need to win the match; the achievement unlocks as soon as you make your fourth kill. You also don't even need to survive; I died after three kills but my torpedoes destroyed my fourth ship and then we lost the match.

I used the premium tier III Iwaki cruiser - I would recommend sticking to tiers III-IV for this as the matches are faster and more furious. It's a mixture of aggression, tactics and luck. Try to stay far enough away from enemy ships so as not to be seen but close enough to be within torpedo range. With enough luck and carefully placed torpedoes you can make consistent hits on battleships enough for 3-4 kills and hopefully your teammates won't finish them off before you do.

- Keep moving and keep changing direction
- Keep launching torpedoes even if targets are out of range (sometimes they turn into them)
- Use smoke tactically and prey on the damaged and weaker ships
- If you're spotted retreat while weaving and dodging and launch torpedoes, don't fire main cannons

I found the Japanese Kuma and Isokaze to be reliable killers if you don't have any premiums, also the German V-170 has deadly killing power. Also be sure to have a good destroyer or cruiser commander; I used Tanaka and Von Spee.

The achievement is not completely described. According to wargaming (I was confirmed by a tick) it is not enough to do 4 kills in a game, you have to win the game at the end.
Achievement pops after the game is over.