I was trying to add it to an advent ship to start, and yes, I replaced one of its abilities with the AbilityIncendiaryShells in it's entity file. Still not working though. Anything else you could suggest trying?

Diplomacy 1.0 with no other mods enabled. Advent Carrier was the ship. Hope you have better luck then I have.

After further testing I am noticing this too, I can't seem to get this skill to work on anything besides the Marza. Gonna test a different TEC capital ship and see if that works.

For testing I upped the damage to 3000 per second so I would immediately be able to tell if it was applied and working but nothing so far.

this is another if you don't want any requirements

maxNumLevels 1
levelSourceType "FixedLevel0"

so, the verdict- can't be done? I still haven't figured out how to actually give the ability to LRM Frigates and have it WORK.

I made a whole reply but for some reason the forum is now forcing me to use double space and when I copy/paste my .entity files it is excluding the different lines making it look like one big block of text.

Can't seem to figure out how to post like normal. But here goes....

Buff file: TXTentityType "Buff"onReapplyDuplicateType "KeepOldBuff"buffExclusivityForAIType "ExclusiveForAllPlayers"isInterruptable FALSEisChannelling FALSEnumInstantActions 1instantAction buffInstantActionType "ApplyBuffToTargetOnWeaponFired" instantActionTriggerType "OnWeaponFired" numWeaponClasses 2 weaponClassForWeaponPassive "AUTOCANNON" weaponClassForWeaponPassive "BEAM" passiveWeaponEffectChance Level:0 1.000000 Level:1 1.000000 Level:2 1.000000 buffType "BuffIncendiaryShellsTarget" targetFilter numOwnerships 1 ownership "Enemy" numObjects 3 object "CapitalShip" object "Frigate" object "PlanetModule" numConstraints 0numPeriodicActions 0numOverTimeActions 0numEntityModifiers 0numEntityBoolModifiers 0numFinishConditions 0
Ability file:TXTentityType "Ability"buffInstantActionType "ApplyBuffToSelf"instantActionTriggerType "AlwaysPerform"buffType "BuffIncendiaryShellsSelf"effectInfo effectAttachInfo attachType "Invalid" smallEffectName "" largeEffectName "" soundID ""needsToFaceTarget FALSEcanCollideWithTarget TRUEmoveThruTarget FALSEisUltimateAbility FALSEmaxNumLevels 3levelSourceType "Intrinsic"minExperienceLevelRequired Level:0 0.000000 Level:1 2.000000 Level:2 4.000000aiUseTime "Invalid"aiUseTargetCondition "Invalid"isAutoCastAvailable FALSEisAutoCastOnByDefault FALSEpickRandomPlanetToExploreForAutoCastTarget FALSEignoreNonCombatShipsForAutoCastTarget TRUEonlyAutoCastWhenDamageTakenExceedsPerc 0.000000useCostType "Passive"researchPrerequisites NumResearchPrerequisites 0nameStringID "IDS_ABILITY_INCENDIARYSHELLS_NAME"descStringID "IDS_ABILITY_INCENDIARYSHELLS_DESCRIPTION"hudIcon "HUDICON_ABILITY_INCENDIARYSHELLS"smallHudIcon "HUDICON_ABILITY_INCENDIARYSHELLS"infoCardIcon ""

Now so far I have only been trying to get this to work on the Halcyon Advent Carrier. Zombies post makes sense as to why it wouldn't work on a frigate. I can't seem to get it to apply the effect unless the ship is using missiles or autocannons regardless of how the file is changed. The problem appears to be that it does not want to function with beams, lasers, or plasma.

set numweaponclasses to '0', if his suggestion does not work, and delete the classes.

Exactly which ship are you applying this to, and can you upload the files (like mediafire) so that we can get a better look.

First add the weaponclass back as it currently doesn't work with any weapons, also note that it only works with capitalships because of the levelsorcetype being insentric and it is currently in the ultimate ability slot, try and change it to one of the other ability slots (if you add it to the 5th then make it either the levelsourcetype to either a fixedlevel0 or research).

Also describe how it doesn't work, does it not show up ingame or does it simply not add the wanted effect?

agree with gruntmaster1, it may not even work with that factored into the abilityincendiaryshells.entity

except pirates only use autocannon and missiles

Well, after alot of testing and trying I finally figured out what the problem is.

I believe there is something fundamentally wrong with the set of reference files I was using. In specific when I put BuffIncendiaryShellsSelf.entity file into a mod without changing any of the file the Incendiary Shells ability stops functioning all together, even when I try using the Marza Dreadnought(The default ship for the ability) it wont function.

I tried your files and can also report they are working fine for me as well. Going to attempt converting my gameinfo files from binary again.