Well, someone asked a question about skill training earlier, namely could you make a 'pump' that works up sword skills, or something. Well, here's a more.. Literal interpretation of the idea.
Custom Building:
[BUILDING_WORKSHOP:TRAINING_DUMMY]
[NAME:Training Dummy]
[NAME_COLOR:7:0:1]
[WORK_LOCATION:1:1]
[DIM:1:1]
[BUILD_LABOR:MASON]
[BUILD_KEY:CUSTOM_SHIFT_D]
[BLOCK:1:0]
[TILE:0:1:'^']
[COLOR:0:7:0:1]
[TILE:1:1:'l']
[COLOR:1:7:0:1]
[TILE:2:1:'t']
[COLOR:2:7:0:1]
[TILE:3:1:'T']
[COLOR:3:7:0:1]
[BUILD_ITEM:1:STONE:NONE:NONE:NONE][CAN_USE_ARTIFACT]
[BUILD_ITEM:1:BUCKET:NONE:NONE:NONE][EMPTY]
Custom Reactions:
[REACTION:TRAIN_SWORD]
[NAME:train with sword]
[BUILDING:TRAINING_DUMMY:CUSTOM_S]
[REAGENT:A:SWORD:NONE:NONE:NONE:NONE][PRESERVE_REAGENT]
[SKILL:SWORD]
[REACTION:TRAIN_SPEAR]
[NAME:train with spear]
[BUILDING:TRAINING_DUMMY:CUSTOM_SHIFT_S]
[REAGENT:A:SPEAR:NONE:NONE:NONE:NONE][PRESERVE_REAGENT]
[SKILL:SPEAR]
[REACTION:TRAIN_AXE]
[NAME:train with axe]
[BUILDING:TRAINING_DUMMY:CUSTOM_A]
[REAGENT:A:AXE:NONE:NONE:NONE:NONE][PRESERVE_REAGENT]
[SKILL:AXE]
[REACTION:TRAIN_HAMMER]
[NAME:train with hammer]
[BUILDING:TRAINING_DUMMY:CUSTOM_H]
[REAGENT:A:HAMMER:NONE:NONE:NONE:NONE][PRESERVE_REAGENT]
[SKILL:HAMMER]
[REACTION:TRAIN_MACE]
[NAME:train with mace]
[BUILDING:TRAINING_DUMMY:CUSTOM_M]
[REAGENT:A:MACE:NONE:NONE:NONE:NONE][PRESERVE_REAGENT]
[SKILL:MACE]
Additions to entity_default.txt [ENTITY:MOUNTAIN]:
[PERMITTED_BUILDING:TRAINING_DUMMY]
[PERMITTED_REACTION:TRAIN_SWORD]
[PERMITTED_REACTION:TRAIN_SPEAR]
[PERMITTED_REACTION:TRAIN_MACE]
[PERMITTED_REACTION:TRAIN_AXE]
[PERMITTED_REACTION:TRAIN_HAMMER]
You get the idea. One caveat though, is that ANY dwarf who is not forbidden, somehow, from using the Training Dummy will use these 'reactions'. Further, their skills will increase at a much slower speed than Sparring with other Dwarves, but there's very little chance of injury.