V-Grade (The Hueco Scale) - USA

The technical grade named V-Grade (The Hueco Scale) for bouldering, was conceived by John 'Vermin' Sherman.
The V-Grade system start from V0 and end at V16. The V0 is easy and V16 is hard, also the grade have postfixed "-" for easier or "+" for harder. The VB grade is designate for "beginner" or "basic" and it is easier than V0.
This technical system for bouldering is like the others, don't take into account the fear or danger. Due to this problem in guidebooks we will find separated noted when boulder is dangerous, the terrain underneath has some problems or if the landing area have some problems.

Gill B-Grade (Peak)

The  technical grade named B-Grade (Peak) for bouldering, was conceived by John Gill (in 1950).
The B-Grade system start from B0 and end at B16. The B1 is easy and B16 is hard. The B0 grade is designate for "beginner" or "basic" and it is easier than B1.
The B-Grade system have historical connotations and it is respected, but this system has some limitation in modern.

Fb (Fontainebleau) - French

The Fb (Fontainebleau) system is the most used in Europe, first time used in France to classify climbing in Fountainebleau forests.
The Fb (Fontainebleau) system start from 3 and end at 8c+. 3 is easy and 8c+ is hard, also the grade have postfixed "-" for easier or "+" for harder.