The Luckiest Dumb Doctor - Chapter 484 - Gift-Giving_1

A scientific genius named Thomas Harrier was transmigrated to an imperial prince body after a car accident that took his life. He found out that he is in a world similar to our own with a timeline akin to early twentieth century. The body that he is occupying was the imperial prince of a failing empire who suddenly rose to power after a successful assassination attempt of his father. Unaware that the attack is just the beginning of what is to come. He faces many challenges throughout. Will Thomas Harrier be able to live his second life in peace while running an empire and getting it back to its former glory? Or will he succumb into a conspiracy lurking within the country's borders?

Expect some:

Cold war era techs.

Super battleship with advanced electronics, propulsion, and fire control systems?
Helicopters?
Missiles?
Modern medicines and equipment?
AC-130?
A nuke?
Challenger or Abrams or Leopard?
F-4 Phantom or MIG-21?
Colored TV's.

Everything!!!

PS. Cover not mine, I just found it on google.

I’m not a gamer. In fact, I barely touched games—never had the time or interest.I’m a 23-year-old college dropout, part-time construction worker, and full-time avoider of adult responsibilities.That is, until my little sister nagged me into trying a romance simulation game called Echoes of the Crimson Throne.I played it. Liked it more than I expected. I even completed it.And the next thing I knew… I woke up inside the game.Not as the hero.Not even as a love interest.I was now the personal attendant of Alice Draken—the villainess, the Prince’s fiancée, and the iron-fisted Ruler of the North.A woman whose downfall was guaranteed... unless I do something about it.

Princess Leah wrote a suicide note ahead of her wedding.

Every player had the same starting resources.Everyone could choose to explore 10 rooms every day. One room could be dangerous while the other might contain resources.Players must do everything they could to survive.After he finished reading the instruction, Li Zheng heard a voice next to him. “Selecting a random daily reward…”“Congratulations. You have obtained a silver chest that contains a silver-grade blueprint for the Ordinary Detector, and a few other resources.”“Congratulations. You have obtained a bronze chest that contains a bronze-grade blueprint for the Air Purifier, and a few other resources.”“Congratulations. You have obtained a platinum chest that contains platinum-grade blueprints for the Ionized Knife, Intermediate-grade Genetic Cultivation Liquid, and TJP Shield, and many other resources.”“Congratulations. You have obtained a hyper legendary chest that contains…”Li Zheng looked at the colorful chests in front of him and grinned.