Hi Jarek, Ok, I think I understand. You want the fire effect to only affect certain units and/or structures? Under the skill section, the flag "not_usable_on=" flag in the skill file will take a comma separated list of all the units/structures that the skill cannot be used on. Also, for Ian, it might be nice to jot down a new skill flag called "Only _usable_on=" which has a comma separated list of units that it can be used on. This helps when you got dozens upon dozens of units and you only want a skill to affect a few. So in that sense, Jarek, you don't need to worry about making the units respond to the health of structures and buildings, just the skill flag. Hope that works out. al -----Original Message----- From: ian-reeds-games-bounce@xxxxxxxxxxxxx [mailto:ian-reeds-games-bounce@xxxxxxxxxxxxx] On Behalf Of Jaromír Pšánský Sent: Monday, August 05, 2013 2:27 PM To: ian-reeds-games@xxxxxxxxxxxxx Subject: [ian-reeds-games] problems with fire effects hi all. I have some buldings and enemy soldiers and bowmans. I would like that AI use fire effects against this buildings, but not use against my units for example knights, archers, and some one. Do you have somebody any solution? I do not know what I have repair in my skills or effects. I have build_health for buildings, health for units. Thank you Jarek