Flatten

 is an active skill that that can be learned by Berserkers at level 4 and can be ranked up at later levels.

can be performed with an axe by the Berserker for a high chance to knock down opponents. This skill is useful in both PvE and PvP, but moreso the latter. Although other experienced PvPers will recognize the skill and know to get out of range, it is important for the berserker to land Flatten to have a higher chance to catch up with the opponent to use other skills.

Amount of damage dealt varies dependent on skill rank.

Rank table
To upgrade to the next rank, one must find a Tactics Instructor and pay a certain price of gold dependent on rank.

Glyphs
To glyph, a glyph must be obtained and learned only once. At level 60, a character has 50 glyph points available to spend on all available berserker glyphs. Most glyphs, specifically common glyphs can be purchased from a Glyph Master, while fine glyphs must be looted from enemies.

(Disclaimer: As NPC shop prices vary depending on a variety of factors, the prices below are subject to variation. Only take them as benchmarks.)