2007-05-01
Fortification is to lands what Equipment is to creatures. Except for the difference regarding what kind of permanent it can affect, Fortifications and Equipment follow the same rules.
2007-05-01
If Darksteel Garrison and the fortified land would be destroyed at the same time, only Darksteel Garrison is destroyed.
2007-05-01
The second ability triggers whenever the fortified land becomes tapped, not just when it's tapped for mana.
2007-05-01
The triggered ability is mandatory. If you don't have a creature to target, you must target another player's creature, if possible.