DF2012:Object testing arena
The object testing arena is a fun place; you can test things, or just have some fun carnage. The arena is accessed through the main menu. Note that the object testing arena is not the same as an arena created in fortress mode.
 Spawning creatures
Creatures can be spawned while in the loomenu. Press to create a creature. Select the creature type, skills and equipment, and then press . Press (or whatever you bound "leave screen" to) to cancel without creating the creature. You cannot delete creatures. You can, however, press then to create a stone wall, instantly killing anything on that tile.
 Inventory and skills
While in the creature placement menu, it is possible to add skills to your creatures such as the fighter skill. It is also possible to add weapons, ammo, and armour to your creatures. Creatures unable to use the weapons given to them will drop them upon unpausing, but creatures such as dwarves will happily use the weapon as long as they at least have dabbling in the weapon skill. You can also set exactly how much of a certain item you want when you select it, by using theor keys, which is the only way to get a creature to hold more than one piece of ammo, as the arena lacks an option for spawning quivers or backpacks.
It is possible to 'Team' creatures up by pressingand in the Creation menu which is shown on the top left hand side. There are 99 teams, as well as "Independent", which is the default and acts as every creature for himself.
In this way you can create simulated battles against beasts or enemies. For example, you can test twenty sword-users versus twenty macemen and analyze the battle from the gamelog.txt.
Corpses can be butchered by moving over them and pressing. This can be an easy way to obtain butchering information, although there tends to be a distinct lack of variation in the results (unless the corpse is missing a body part). This is partly due to the fact that no child creatures can be created.
 Fighting in the Arena yourself
Looat any creature, and press to play as them, and to exit back to the main mode.
- The controls here are exactly the same as in Adventurer mode, if you are playing a previous version of Dwarf Fortress you may be unable to set combat preference (as it used to require the same key to stop controlling a unit)
- Attempting to a corpse results in the corpse being butchered.
 Spawning liquids
From the loomenu, press to spawn a 7/7 unit of lava, or to spawn 7/7 water on the currently selected tile. If you place water and then lava in the same tile, they will immediately form a 'Rough-hewn Rock Wall' (i.e. before you unpause, or immediately as you do), resulting in no spillage. However, placing lava and then water simply fills the tile with water, with the same effect as placing water without magma. You can place fluids in a tile that also has a wall in it; the result is a tile with both a wall and 7/7 units of the fluid you placed (water or lava). This combination behaves exactly the same normal water without the wall would, except the area is still considered inaccessible for water to move through.
 Modifying the Arena layout
The layout of the arena zone is stored in <Dwarf Fortress dir>\data\init\arena.txt
This .txt doesnt change the arena space, just what's in it when you enter.
The arena is composed of 9 z-levels (including 0, from Z=-4 to Z=4) of 144 x 144 tiles; the contents of each tile are specified by a single character:
|Water source?1 2|
|7/7 water + ramp|
|7/7 magma/lava + ramp|
- Tile will have no floor unless a pillar/wall is constructed on the z-level below.
- Only seems to work when placed on map edge; behaves identically to otherwise.
There is no way of altering the temperature of the arena directly, and the arena temperature is considerably higher than what would be encountered in most areas of a world generated with the default temperatures. However, tiles that have formerly had lava or magma on them are considerably cooler.
The standard arena temperature is v0.34.11. Note that the temperature of magma that has not been removed remains at . For comparison, the temperature of a subterranean tile is and the dwarven homeotherm is ., and for some reason the temperature of magma-cooled tiles is