Mountains For game purposes, mountainous terrain is devoid of large vegetation and usually occurs at high elevation (4,000 feet or above). A heavily wooded area on the lower slopes of a mountain should be considered as forest, even if the elevation is higher than 4,000 feet. A mountainous region (for determination of movement, encounters, food availability, etc.) begins where the trees end. On Earth, the �tree line� (at about 10,000 feet above sea level) marks the place where deciduous growth gives way to coniferous trees, which are better suited for survival at higher ele- vations and colder temperatures. Beyond the �snow line� (12,000 feet), trees cannot prosper, and only low-lying plants and shrubs can be found; if characters have not reached mountain- ous terrain by the time they�ve climbed this high, they will cer- tainly be in mountains if they go any higher. A barren, rocky slope that begins at relatively low elevation and rises high above the surrounding area can also be considered as mountainous ter- rain, even if the base of the slope is lower than 4,000 feet above sea level. If hills can be described as irregular terrain, then mountains are downright chaotic. If there is a level spot to be found on a mountainside, it will probably be surrounded on all sides by se- vere slopes and vertical or near-vertical cliff faces. Of course, the lower slopes of a mountain are much less treacherous than the area near the peak - but, as noted above, the lower slopes often contain features (usually trees) that require the area to be classified as something other than mountainous. At any elevation higher than the snow line, some of the rocky surface of a mountain will be covered with snow or ice, making travel even more hazardous. In contrast, exposed rock surfaces at high altitudes can become much warmer than the air tempera- ture because they absorb heat from the sun throughout the day -and on a mountain, there is no such thing as shade except on a slope opposite the sun or in the area beneath an overhang. A mountain is a study in contrasts - warm in some places, cold in others; practically impossible to climb in some spots, fairly easy to negotiate in others; a place of safety or a place of danger, depending on your point of view and how well equipped you are to deal with the terrain. Not all mountainous areas are inherently treacherous, but adventurers who ascend into the peaks without proper planning and preparation are either very desperate or very foolish.