President Barack Obama and Republican Mitt Romney square off Wednesday at a University of Denver sports arena for the first of three presidential debates that could be crucial to the 2012 election.

Given the central importance of the economy, this debate—focused on economic and domestic issues—may well be the most important. Here’s a guide to the basic details, plus the issues likely to be raised, an assessment of the candidates’ positions and a look at their vulnerabilities.

The Romney campaign is hoping for a bump from the debates, and both campaigns have been playing down expectations so that their candidates can outperform in the public’s eye.  Mr. Romney faces more pressure to win the debate, while Mr. Obama may be content to hold back and produce a steady but safe performance. Polls out Tuesday showed most Americans expect Mr. Obama to win the debate. Past debates have produced memorable moments and focus will be both on the major points of disagreement and on the little things, like personal style and poise.

Read more at The Wall Street Journal