Designing cooperative levels

[Ixnatifual]

Being sort of a newb to level editing, I'd like to have some guidelines when making my maps support cooperative play.

When I look at id's maps, the only significant change seems to be that there are more guns in the levels, and that they come earlier than usual. There's of course also the occasional cyberdemon in the poison pool.

Why are there more guns anyway? It's not like there's more monsters.

[Graf Zahl]

That's because id never bothered to make a 'real' co-op setting for their levels. They only had a 'multiplayer' flag, not separate ones for each game mode. The additional weapons are for deathmatch.

[Ixnatifual]

So all there is to making a ZDoom level good for cooperative play is to place additional starting locations?

[Graf Zahl]

In ZDoom you can place specific CoOp items. But this feature was only available since Hexen or Boom but not in the original Doom levels.

[Ultraviolet]

I reccomend stacking the player starts really close and providing only rocket launchers and spectres throughout the level.

[SirTimberWolf]

I *personaly* would suggest making areas that are only accessable in coop, and dont include a computer map... Ammo, maybe 1.5x the ammo of single player.. depending on the balance this can be really fun. monsters, replace some of the weaker monsters with others... zombies with imps... demons with lost souls.. etc.. but thats just me

[David Ferstat]

Also, delay springing your traps until all of the players have entered ...

[The Ultimate DooMer]

And make sure you provide teleporters for players that die and respawn, so they can get back into areas sealed off from the outside.

Another thing I do is place all the keys at the start of the map, but in a hole in the floor with no lower textures, and make them rise up when the actual key in the map is found. (saves a lot of time when you die and respawn)

I have placed all available weapons at the start of maps in the past, but only in episodes/megawads (and obviously not including weapons that haven't appeared in the episode yet).

Also, if an item is put down in a map for a specific reason (eg. rad suits for sludge passage, megaspheres for big battles), put extra ones down for the other players.

[Ultraviolet]

Don't simply provide teleports. Since this is ZDoom, build one teleport station (one teleport with a control panel) that, each time you use the control panel, cycles through all the teleport destinations the players have unlocked (by pushing a switch at the destination to activate it). While you're at it you might as well have each unlocked destination also function as a teleport station to the other destinations as well, once the source station is unlocked of course.

monsters, replace some of the weaker monsters with others... zombies with imps... demons with lost souls.. etc.. but thats just me

Don't replace, just ADD. If you take out the weaker monsters such as zombies and shotgunners you'll affect the ammo balance and have to compensate more by adding pre-existing ammo. Preserve as much monster-carried ammo as possible so the player has to work for it and can choose ammo balance to a degree during gameplay by either avoiding conflict with lesser monsters, killing them with heavy weapons to gain more small-arms ammo, or killing them with said small-arms ammo to gain more.

So uh... if you have a group of three zombies, add an imp or two. If you've got three shotgunners, add one demon or something. Just don't take out the monster ammo sources if you can help it.

[Risen]

UD:No need. In ZDoom, once you get a key, you keep it even if you die. You also keep every weapon you've picked up and get 25 ammo for each type you can use. (Personally, I don't like that... it's rather advantageous to pick up a rocket launcher and intentionally kill yourself with it)

I agree with UltraViolet on the monster issue. Don't just replace, add more. But don't spread them out, keep them in the same attack groups. Since multiple players have the ability to unload much more ammo much faster, the fights become much shorter. (My brother and I once opened a fast door with a revenant directly behind it. Given the level so far, this may have been intended as surprising and a challenge. We both unloaded our double-barrels instantly and leveled it on the spot. No challenge there.)

Always design your levels so that people can get in somehow from the outside. Recognize that people can and will stand underneath trap doors to keep them open if they can figure out it's a trap. Always expect players to be anywhere at any time. With ZDoom, players have Z-height. If possible, players may stand on each other to reach out-of-the-way areas. Expect players to try, but don't require it. Don't use one-time-use objects like teleports unless you're certain no one else will need to use it. Don't use multiples of the same player starts (also sometimes referred to as mannequins). It often messes things up.

Hope that helps. I love a good co-op.

[HotWax]

You can also use scripting to find out how many players are playing the map, and adjust things to compensate. For example, a puzzle that normally requires a few switches in different areas to be hit can now require that they be hit at near the same time, requiring cooperation from the 2 (3, 4, 7, 8) players in the map. You could even make areas that branch to different paths, with one player in each path, giving a sense of a single-player miniadventure for each player, but all players can only proceed after everyone is done with their segment. It's an unfortunate fact that coop has gone overlooked for a long time by mappers and players alike. I think if players were given a map that plays totally differently during coop, requires teamwork and is even more fun when you bring friends along, there'd be alot more people willing to find partners to coop with.

[Smuggle]

hah. many monsters

[Kuroshi]

You also keep every weapon you've picked up and get 25 ammo for each type you can use. (Personally, I don't like that... it's rather advantageous to pick up a rocket launcher and intentionally kill yourself with it).

I don't like that either as it is really unbalanced. Like you said, you get a lot of firepower for the rocket launcher, but not enough cells for even one BFG shot. What would work best IMO would be to have an ammo count like what it would be if you recollected all the weapons you died with (i.e. you die with all the weapons, you respawn with 70 bullets (50 init plus chaingun pickup), 16 shells (Shotgun and SShotgun), 2 Rockets (Rocket Launcher), and 80 cells (Plasma Rifle and BFG)).

As for monsters, adding more is definately the way to go as with two players the firepower of the weapons essentially doubles. I think Id added the odd Cyberdemon in their levels because several people can easily take one down if working together. Four skilled players welding SShotguns can make quick work of a Cyberdemon for instance as he tends to get hurt very often by the SShotgun blast. This is especially true if they line their shots up in sequence. One way to test coop mode possibly would be to make a DEH or BEX patch that increases the rate of fire for the weapons. Also realized that the players must split up available health and armor in addition to ammo, so make adjustments for that as well.

Also, take a look a some of the good coop level sets such as the Momento Moris and Alien Vendetta and look at the differences between their single and multi player modes

[David Ferstat]

Always design your levels so that people can get in somehow from the outside. Recognize that people can and will stand underneath trap doors to keep them open if they can figure out it's a trap.

Of course, if you don't want players holding doors open like this, replace the doors with crushers.

[The Ultimate DooMer]

You also keep every weapon you've picked up and get 25 ammo for each type you can use. (Personally, I don't like that... it's rather advantageous to pick up a rocket launcher and intentionally kill yourself with it).

I don't like that either as it is really unbalanced. Like you said, you get a lot of firepower for the rocket launcher, but not enough cells for even one BFG shot. What would work best IMO would be to have an ammo count like what it would be if you recollected all the weapons you died with (i.e. you die with all the weapons, you respawn with 70 bullets (50 init plus chaingun pickup), 16 shells (Shotgun and SShotgun), 2 Rockets (Rocket Launcher), and 80 cells (Plasma Rifle and BFG)).

As for monsters, adding more is definately the way to go as with two players the firepower of the weapons essentially doubles. I think Id added the odd Cyberdemon in their levels because several people can easily take one down if working together. Four skilled players welding SShotguns can make quick work of a Cyberdemon for instance as he tends to get hurt very often by the SShotgun blast. This is especially true if they line their shots up in sequence. One way to test coop mode possibly would be to make a DEH or BEX patch that increases the rate of fire for the weapons. Also realized that the players must split up available health and armor in addition to ammo, so make adjustments for that as well.

I don't know if it'll work or not, but you could use scripting to take everything away and give them the weapons/ammo that you said when they respawn. The trick would be disabling it at the start when the players first enter a map, but I think a simple variable would take care of that - ie. make the weapon script work only if i = 1, set i = 0 at the start of the map, and have a line trigger near the start that sets i = 1. Make it player-specific of course.

Code: Select all

int i = 0;

script 1 ENTER

{
if (i == 0)
    {
     terminate;
    }
if (i == 1)
    {
     TakeInventory (PlayerNumber, "*dothisforallweaponsandammo*", 600);
     GiveInventory (PlayerNumber, "Chainsaw", 1);
     GiveInventory (PlayerNumber, "Shotgun", 1);
     GiveInventory (PlayerNumber, "SuperShotgun", 1);
     GiveInventory (PlayerNumber, "Chaingun", 1);
     GiveInventory (PlayerNumber, "RocketLauncher", 1);
     GiveInventory (PlayerNumber, "PlasmaRifle", 1);
     GiveInventory (PlayerNumber, "BFG9000", 1);
     }

}

script 2 (void)     // run this when player crosses a linedef in the first room

{
i = 1;
}

I'm not sure about the PlayerNumber bit, but there is a way to do it if that's wrong.

(btw, one skilled player wielding a super shotgun can make quick work of 4 cyberdemons....HR2 map 24 ending)