Introduction of Dota levels
Dota 2 is not running on the Source 1 engine anymore. The new Source 2 engine has been in the beta phase for a few months and was tested by several Dota 2 players who played normal games or custom games in the beta mode. As of now the beta is over and Reborn is the new Dota 2 main client, which means that all players will now play Dota 2 using the Source 2 engine. Valve did not only release the new engine but also introduced a number of new options, settings and rewards.
One of the new introductions were the Dota levels. They are similiar to the kind of achievement tracking we see on the consoles. As Valve said the Dota levels are "the culmination of all your accomplishments in Dota". Dota Levels are displayed as a badge on your Dota Profile based on your level, and are gained by earning trophies and playing matches. A specific amount of trophy points will ensure players to get new trophies, rewarding certain achievements such as playtime and wins in Dota 2. These trophy points will also contribute toward increasing the levels. 100 trophy points will increase ones Dota level by 1.
There are different ways to gain trophies and Valve already announced there might be new trophies in the future. For now you can earn trophies by playing matches, perform various feats or participate in events. Remember that every trophy counts and contributes to your Dota level. The two most recent announced trophies are the "Experience trophy" and the "Battle Veteran trophy", which reward you for just playing Dota or reward you for gaining Battle points.