objects which could pose a danger to players and officials (but not including marker flags, which are typically of soft construction). The referee (and their assistants) generally have full authority and responsibility for all players and other officials inside the playing enclosure. Fences or ropes (particularly at amateur clubs) are generally used to mark the extent of this area, although in modern stadia this may include the entire arena floor or other designated space. The Laws, above all, require that the playing enclosure's surface be safe, whilst also permitting grass, sand, clay, snow or conforming artificial turf to be used; the surface would generally be uniform across both the playing area and perimeter area, although depending on how large the perimeter is, other surfaces such as dirt, artificial turf, etc. may be used outside of a "sliding" perimeter from the bounds of the playing area. Playing area For the most part, the "playing area" is where the majority of play occurs. The ball is generally considered live whilst in this area, so long as players do not infringe, with special rules applied to specific zones of the playing area. The playing area consists of: The 'field of play", bounded by (but not including) the sidelines and goal-lines, and One "in-goal" area at each end of the field, each bounded by, but not including, the extensions two parallel sidelines (known in this context as the "touch in-goal" lines) and the dead-ball line, and its other bound being the goal line (or "try line") which is included as part of the "in-goal" area. Field of play A typical "field of play" is generally 100 metres long by 68–70 metres wide for senior rugby, depending on the specific requirements of each ground. The Laws require the field of play to be between long, with a width of between . As other football codes, such as association football and rugby league, have specified a preferred or standard 68 metre width, this is often used unless a ground has been specifically designed to accommodate a 70-metre rugby field. 100 metres is the typical length, with a line (see below) often marked at halfway with "50" on it, representing 50 metres from each goal line. The variations have been allowed in the Laws, possibly to accommodate older grounds (perhaps even pre-metrification when yards and feet were specified) and developing nations. Other lines and markings The field