A GM screen has two purposes:
- To provide information that I need at the table so that I don't have to open a book.
- To add to the atmosphere of the table.
For #1, what I need changes over time. When I'm first learning the system, I'll need rule references for combat, chases, DCs, etc. Once I've memorized those, I need useful charts and references to common things that I just can't quite remember: Conditions, a list of skills, price lists for common purchases (food, inns, transport, goods and services). Eventually, I'll be looking for a toolkit that aids in improvisation, like generic monster stats and NPC traits. I also end up needing a place to put information about the PCs.
For these reasons, I end up using custom GMs screens, or at least clipping custom pages to my screen. But it would be interesting to explore designing multiple screens for different levels of experience, or professionally made clip on (or magnetic) panels for "upgrading" sections.
As for #2, nice art, or at least good layout and graphic design go a long way.
A few other points that make for a great GM screen:
- Design matters. Information that can't be found quickly and intuitively may as well not exist.
- Have some white-space and art to break up the wall of data, but keep information density high. It's a dashboard, not a novel or a gallery. This will be a difficult balance.
- Panels are your first and best organizational unit, followed by columns. Use them to gather related information, and don't let them bleed into each other.
- Use different layouts and presentation-types on different panels. For example, one may mostly be tables, while another may be an infographic, and a third a list of callout boxes. This variation helps make each part distinct, and thus more quickly differentiated at the table.