I think the best option is to use Ioquake3

Ok. Why? What are the reasons? I tried ioquake3, but stuck with QVM, don't know how to make scripts or logic for weapons/AI working outside from compiled qvm files.

DarkPlaces.

https://icculus.org/twilight/darkplaces/

Anything you suggested above is going to be painful and hard as hell. You are barking up the way wrong tree if you expect to find anything resembling easy with any of the engines you named.

You should use something newbie friendly that has video tutorials for someone just starting out.

Like Unity3D and how it is tailored to newcomers.

https://unity3d.com/

Thanks, but again what is reason for that? Maybe I really should rephrase question for that..."I need advice which engine is best capable to support my criteria, why I should choose it and possibility how to implement criteria in engine". For example, I tried ioquake3 - native bots and q3maps support, but I'm stuck with QVM - all weapon, AI data & player char stored inside *.qvm binaries, and I don't know how to make it work outside without rewriting/recompile data inside it every launch. Darkplaces is maybe good for editing entities for weapons & game mode, but have weak AI, bad q3map support, weaker multiplayer gameplay fps. And I'm also not sure how to implement those things in Darkplaces exactly.
I was also trying to implement all above in Unity3d, but as far as I know Unity3d is not working with files outside resource packs with engine and it's almost impossible to implement my criteria. IdTech* based engines are closer for "edit after build" and overall mod support. The point in this build/fork is to make editing of weapons, bots AI & arena player chars easy for average user, not really for me to code that. But of course it's better to take closest "half-ready" engine for my criteria than to build something from scratch
Anyway thanks for support.

darkplaces can do everything as an engine that u have listed.
it is up to u the modder to code/direct it

alternate engines to try,

lumberyard

Unreal

just build an engine. Then everything you want to do will be as possible as you make it. Ogre3D comes to mind. It has bsp parsers. Just write some game logic and engine manipulations for Ogre.

I have the impression you might be getting ahead of yourself. You don't step foot into a kitchen and make Coq au vin for your first meal.

My advice is this: Use a modern toolset like Unity or Unreal, but start by making something smaller, like micro-games. make each micro-game somehow feature just one or two of the things you want to tackle in your dream-project.

I know this isn't the sexy answer you were hoping for, but trust me on this. I know what I'm talking about. You gota start by just mucking around, forum lurking, example-picking, and making friends. Get messy, be patient.

www.amon26.itch.io

Darkplaces might be the answer, I need to check compatibility for quake3 maps for using it with bots. Lumberyard & Unreal might work out as well

Tried Ogre3D a year ago, samples from forums and my own attempts was clunky and slow. And anyway I was trying to make things easy for me and people to mod it in future. Game should be fast and easy modable, high quake3 maps/bots compatibility. That is the reason why I think of Quake* engines in first place to make things work out

Thank you for a great advice
Maybe you are right, I might rushing things up I should implement simple things from my criteria, and then decide how to move and in which direction.
I already tried to make small games in Unity, but the "edit weapon/AI damage, logic" is not possible out of *.resource packs. But Unreal, darkplaces or ioquake3 might work in that direction - I just need to find/understand which one is the closest for that
I hope I can find support here in this thread (or forum at least) to solve some more exact problems on my way

well, ogre was just one example. There are lots of engine API's out there.

@make easy
wouldn't it be really easy if the only scripts to modify are the ones you put on top of a fully functional engine API. For instance, my flash quake engine is a whopping 3 classes (on top of hundreds). But I don't need to fuck with the 100's I just need to utilize them, and not all of them at that.

It sounds like you want to get work done without getting your hands dirty.

quakec and csqc should be able to do most, if not all of what you want, but if you want no fuss no muss, that aint gonna happen.

On the other hand if you want CSQC support (and you do), the only engines providing that are FTE and Darkplaces.

Quake3 bots arent going to work out of the box, there are no AI solutions premade, anything you want to do for AI, you're going to have to do yourself.

Vanilla QuakeC has weapon stuff all in one place, but its a mess. So you'll probably have to do that yourself too.

In short, you can do all of these things, but if you're looking for easy....this isn't the right project.

It's quite close to what I want to do. I want to make it possible to edit/add small scripts that creates new entities on a basis of (like in IdTech4 - Doom3, Quake4, Etqw; 4089: Ghost within). So I don't want to make something really big and complex. First add possibility to make that script system work, then add any amount of entities (weapons, monsters, bots, map entity) based on few basic types. Of cource even that wouldn't be easy, but perhaps it will be easier for average user to add content So I'll just try engine by engine writing small mods one by one, and continue where it fits best. For now I'll try Darkplaces/Xonotic, then Ioquake3 and so on.

I understand that it's not @easy one Just want to understand what possibilities I have and which engine is better, than another for this project.
I'll start with Darkplaces/Xonotic and first make scripts work for weapons.
About bots:
For Quake3 I wanted to go "from bots to monsters" way - add new type of bots on top of existing AI system, which acts like monsters. I tried to edit behavior/priorities for new bots. So I wanted them act like monsters(slow and stupid) until they start attack. Instead I've got just stupider bots
For Darkplaces I want to go "from monsters to bots" - take bots from Xonotic and "mix" their behavior with monsters. But Xonotic multiplayer maps are "waypoint" system, and quake3 have Galdiator bot AAS system, so on any non-native map they just stand and shoot. Either I need to change bots for adaptive ones, or add "waypoint" to every map