The London System is quite possibly one of the easiest ways to set up a decent position for white. It is a great opening for beginners, because it creates many opportunities.
The opening starts with 1. d4 and a typical response from black, d5. This immediately activates the white c1 bishop with a long angle across the board. Move two is typically 2. Kf3 and black’s response is Kc6 or Kf6. Move three finishes the main portion of the opening with 3. Bf4, and the response from black varies between moving the remaining unmoved knight or moving Bg4 attacking the Knight at f3.
Example: 1. d4 d5 2. Kf3 Kf6 3. Bf4 Bg4
Once the London System is set up there are numerous variations in including 4. e3 – allowing the development of the f1 bishop, 4. Kc3 – developing the b1 knight, and 4. h3 – pressuring black to capture the white knight at f3, or to retreat back to h5 or f5.
Aggressive players might want to move 4. e3 in order to open a lane to move the f1 bishop to quickly allow a kingside castle. Safely tucking the King away allows this opening to continue to develop an attacking position.