This is awesome! I'll definitely be using this system a lot when I play

Although it does seem like a good idea, the hero system feels simply like a less modular form of the main system. The idea of being able to set particular npcs to spawn only a certain amount of times is good, but its killed by the fact that you cant edit their scale or any other stat.

I feel a better idea would be to integrate an additional setting into the main npc list that allows players to simply set a spawn cap for each kind of npc:

so for instance, much like the health setting, you could have a number box that allows you to set the maximum possible amount of npcs for that particular entry in the list, with 0 being an infinite amount (default as it is now).

So i could have for instance an entry in the list that is npc_alyx spawning with weapon_smg1 with the maximum being set to 1, this is essentially the exact same thing as your hero system but it is more modular, as i am also able to set damage multiplier, scale, etc.

Just below this entry i could have npc_citizen with weapon_shotgun and a maximum of 30, so only 30 of those npcs can be spawned at any given time.

And just below that i could have npc_zombie with a cap of zero (default) which is only limited by zinv_maxspawn.

This allows for player to fine tune spawns a lot more. Where as before to limit the amount of npcs you have, you need to set the % chance really low (which is unreliable), now you can have the percent chance be say 10%, with a max of 5 npcs, so although you can have up to 5, it is unlikely that that many will spawn.

or you could have a particular npc set at 100% with a cap of 1, for when you want a particular npc ALWAYS in the field, but only 1 of them.

Sorry if thats a confusing mess, i didn't really proof read it, but the point im trying to make is that adding a maximum spawn limit box for each entry in the list, that works within the confines of zinv_maxspawn would be a much more effective and customisable way to go about this. As it would not allow the player to just add heros, but a variety of other types.

And by working within the confines of zinv_maxspawn i mean, if i have an npc max spawn set to 30, then there is a maximum of 30 of that entry able to spawn, out of the 500 possible npcs on the map at once (if zinv_maxspawn is at 500, mine always is ;) )

Damn, I hadn't thought of that. I opted for a different system because the normal NPC system was getting a bit too cluttered and I didn't want to add any more parameters.

I'll have a think about making the system a bit more intuitive.

Btw, heroes are counted like normal NPCs so zinv_max_spawn caps them as well.

That's a fair call, but if it gets too complicated all that means is someone has to write a guide. ;)
Do consider it though.

Boss mode. Sounds good.

Can you add a parameter to disable the increased scale of hero NPCs. For some NPCs that are already large enough it is unnecessary.

Yeah I'd like to disable the scale for the heroes, as it's a bit odd to have a gigantic Alyx or Barney show up out of nowhere.

the one and only gripe i have with the hero system is the inability to set the size of the npc. dont get me wrong its good when they are bigger sometimes but it looks weird when a giant npc thats supposed to be bigger comes at you. all in all to be able to have a scale option would be all it needs.