A little help please

A little help please

Hi all making a very nice campaign here but i'm making the next map similar like the one where you have to avoid the blue fires well i wanan know how can you make them do damage like the spikes also. Please tell me i'm pretty expert in this kind of stuff but i still need to learn a bit more

U could give the flames an immolation based spell.
the dutarion in this spell is for in what periods the nearby units get dmg.

or u could make a trigger

Events:
Unit comes withing XXX range of 'flame'
Conditions:
...........
Actions:
Unit - set life of triggering unit to (airthematic) life of triggering unit - XXX

thx but when i try to select the trap fire for it, it won't select only a unit. What now?

I dont know excactly what u mean. then just try a unit type, or variable, or unit group or anything

what i meen is when i pick the event (Unit within Range) and then i pick the number but then the second highlighted space is
of unit How do i make the fire which a doodad work with this option?

ow.. a doodad. i dunno. u shoul make units with ability locust then