ATLAS Trigger Menu and Performance in Run I and Prospects for Run II

The ATLAS trigger system plays a key role in the collection of data for a wide range of physics analysis. The 2012 proton run had significantly larger luminosities and pile-up than 2011, while for the proton-lead run in 2013 it was critical to select samples with low biases. To address these challenges, while maintaining or even improving performance, new algorithms have been commissioned. The trigger strategy and the main algorithms and their performance are described. For the 2015 run, the combination of a luminosity increase and an energy increase will put even larger demands on the trigger system. One new tool to address the challenges will be the addition of a topological capability in the first level of the trigger, implemented in custom electronics. The L1 topological trigger hardware and software architectures and their performance will be presented.