Tips on monster and item placement?

I recently made my first level and so far I've just been placing random monsters and items around the map to test things out. It seems sort of unbalanced. I was wondering if there was a trick to having a good monster / weapon ratio so that the player can be surrounded by potential death while not having to worry about being too overwhelmed or running out of ammo too early.

Playtest, playtest, playtest, playtest. Do your best run and see how much ammo you have left after the level (or even after each give section). Playtest. Do your worst run and think about what you really needed or craved to get through. Playtest. Base your decisions on these, middling out somewhere (or using both runs as the basis for higher and lower settings respectively, then meeting in the middle for Hurt-Me-Plenty). And then playtest some more.

Also, playtest. A lot. Even when you've populated your map with various difficulty settings, don't be happy with it. Playtest until you can't think of any other tweaks to make.

Then hand it to someone else to playtest, playtest, playtest, playtest. ;)

I've always let intuition rule item and monster placement. I think this requires a degree of experience from playing the game rather than designing levels themselves but both certainly help here.

Usually you can't go wrong with giving the player a little too much ammo. Running out of ammunition is one of the most frustrating situations in Doom. Though the frustration can be mitigated if there is a berserk pack or chainsaw early in the map, since they are significantly more powerful weapons than the bare fists and have infinite ammo.

Some people say having too much ammo can make a map feel too easy, but I disagree. Little ammo forces the player to have to watch his ammo closely and make every shot do it's maximum amount of damage as often as possible. This does add a little extra risk to the gameplay, but maps with lots of ammo are easy because of the weapons the player acquires, not the ammo for them. Generally I make ammo pretty easily accessible, but new weapons should have to be "worked" for; meaning the player should have to run around monsters to get to them, or alert monsters or activate traps in the process of getting a new weapon.

If this is your first map, just work on difficulty levels that are applicable for yourself as a player. Chances are the general public are as good at playing Doom as you are. And naturally people will tell you if you're going overboard or if you're starving them for ammo. That'll give you a better idea of what to do when you work on your next map.

I have to agree with 40oz here, but I think he missed an important point. You should really try and not make ammo available until that the weapon it's self can be obtained. This makes for a great indicator to let the player know the missed something when boxes of rockets start appearing but they have no rocket launcher.

Also some tips on monster placement, try and be creative rather than just spamming a lot of monsters. There is really two kinds of difficulty when it comes to monsters, overwhelming masses and dynamic placement. It's really dynamic placement that is key to a map and what that means is you have monsters at various heights, various angles and properly chosen monster types focusing on this aspect will create a much more entertaining and well thought out map.

You know being able to see 100 monsters all at once is usually an easy fight, on the other hand 10 monsters well placed can be a lot more difficult since some might come from behind while your trying to fight some in front, other might be shooting fire balls from an elevated position while a few lost souls are coming out of a hole in the wall you didn't notice yet.

Fine points from everybody here. Also, you should be mentally splitting your map up in terms of micro-battles and sections, and populate monsters, health, and ammo based on those. Figure out how much ammo it takes to bring down enemies, and add enough ammo for each fight. Adjust ammo for each skill level, if necessary (and it will be necessary). Where the player goes and how they move through an area will dictate where items need to be placed.

Each monster has different roles around a map which you should be mindful of:

• Hitscanner enemies (Fmr. Human, Fmr. Sergeant, Chaingunner) serve as minor threats on ground and major threats on ledges and long range. Especially Chaingunners, but anybody who has faced them knows this. Players immediately prioritize these monsters for elimination in large firefights or use them to try to force infighting.
  
• Imps are fairly low-threat both on ground and from afar, due to the ability to dodge their attacks easily.
  
• Demons are great for making the player run around, especially when the player is imperiled by long-range attackers from off the ground. Lost Souls are great for this when you want a similar threat, but need to give it more room to move and are perfect for surprising unwitting players.
  
• If you want to have constant pressure from above the player, a handful of Imps scattered around or something beefy like a Hell Knight or Baron (for extended periods) does the trick. If you want to give those attackers a higher priority for the player, try Mancubi or Arachnotrons. If you want to give the threat more mobility, Cacodemons work here.
  
• If you want to force a player back or keep them in a smaller area, look no further than a slow, beefy guy like a Hell Knight or Cacodemon at the exit of such areas. Even a pack of Demons works here.
  
• Spectres are best placed in dark areas or areas with dark surfaces.
  
• Revenant placement is a bit of a science, and I could write a white paper on that, but I'll settle for the short tips: Revenants are great because of their versatility as an "OH FUCK" threat on ground as well as from up high. Very few of them are needed to make a player sweat, regardless of what any skilled player will tell you. Put them on the ground if you limit the player's ammunition. Put them on ledges if the player has enough to contend with on the ground. They are always a priority to kill.
  
  Their threat changes based on what the player has in their inventory. On ground, high threat if the player only has a single-barrel shotgun or a rocket launcher (due to their quick movement), low threat if the player has a chaingun, super shotgun, or plasma rifle. On ledges, high threat if the player has a chaingun, super shotgun, or plasma rifle (requires concentreated fire at a long-range target), low threat for rocket launchers. BFGs take out hordes of them easily, like the weaker enemies.
  

The following enemies are better placed in situations where you want the player to be delayed from facing them head-on:

• Archviles. Make sure that they get activated while the player is delayed from encountering them in areas where you have just massacred a ton of demons, and they'll start bringing them back, making them more of a threat. In the interest of fairness, always have something the player can hide behind, should they eventually need to go toe-to-toe with one. High priority among the dead, low priority by itself.
  
• Pain Elementals. They make more guys. Don't really need to elaborate. High priority at all times. Their threat is diminished by rapid-fire weapons, though. Rocket Launchers are dangerous to use around these guys.
  

Bosses pose a different problem, since they are pretty threatening on their own:

• Cyberdemons are better in confined spaces rather than open ones. If you give it more space, add more enemies.
  
• Spiderdemons are better from afar rather than up close. Really good at starting infights.
  

There are a few gotchas and pitfalls when adjusting difficulty:

• Do not automatically upgrade Hell Knights to Barons. You are just delaying the player.
  
• Do not just plunk a boss in the map. Every monster in a map should be killable.
  
• To increase difficulty, try not to decrease health pickups. Never remove ammo. Decrease ammo only with difficulty.
  

Best thing to do when adjusting difficulty is to change how the player prioritizes their threats in each area. This makes each skill level fairly unique in terms of gameplay.

That's all I can think of at the moment about monsters and difficulty.

Pottus said:

There is really two kinds of difficulty when it comes to monsters, overwhelming masses and dynamic placement. It's really dynamic placement that is key to a map and what that means is you have monsters at various heights, various angles and properly chosen monster types focusing on this aspect will create a much more entertaining and well thought out map.

You know being able to see 100 monsters all at once is usually an easy fight, on the other hand 10 monsters well placed can be a lot more difficult since some might come from behind while your trying to fight some in front, other might be shooting fire balls from an elevated position while a few lost souls are coming out of a hole in the wall you didn't notice yet.

Who says you can't use overwhelming masses at various heights, various angles and properly chosen monster types?

I've read a lot of complaints about horde maps. The people who complain about overwhelming masses are almost always the people who can't handle them. Some people say less monsters is "strategic" monster placement, and I think that's just an excuse. I agree you can make maps very difficult with a small number of enemies, but it's no more "strategic" or "dynamic" than using hordes.