The tuner is an ingame editor Firaxis provides for Civ 5. It's easy to use: Install the SDK. In steam, navigate to Library -> click "All Games" -> Tools -> Civilization V SDK. . Set "EnableTuner = 1" in this file: \Documents\My Games\Sid Meier's Civilization 5\config.ini . Download Civup (here) and move the contents of Civup\TunerMods\DebugFolder to here: \Steam\steamapps\common\Sid Meier's Civilization V\Debug . Start a game in Civ V. . Open the tuner. An icon for the SDK appears on your desktop (or taskbar) once installed. Click the icon to launch the tuner. For example, I sometimes use the tuner to reveal the map and all resources for debugging: Open the tuner's "Active Player" tab. Click the button "Information Era Techs." The mod adds some features to the tuner. Copy the files from this folder: (mod)\Tuner\DebugFolder to here: \Steam\steamapps\common\sid meier's civilization v\Debug Some of the terrain-editing tools require the mod active to function, but most of the tools work without the mod.