What do I need to make a co-op map? (or to convert a single-player map to co-op)? 

Making a Sven Co-op map is almost the same as making a single-player map. You have monsters and a grouped set of player starts, and a objective to achieve. 

For most standalone maps, the only actual requirement is to put a number of info_player_deathmatch entities into the map. The number can vary depending on the map size but around 6 is usually a good amount. 

It is important to remember that the players will have to respawn at these points regularly, so keeping good contact with the action zone is good for playability, and blocking off access to the combat zone from the respawn is not. By the way, placing player spawnpoints in the air can prevent telefragging if used correctly.

If there are map transitions, there are a few additional requirements, unlike Half-Life Single Player, Sven Co-op does not support players backtracking (returning to a previous map). If the players are allowed to backtrack, the map they return to will be exactly as it was when they first began playing it, and their progress will be reset. Because of this, it is highly recommended that any transitions to previous maps are removed, or disabled using a map CFG (see below).

Since players won't retain weapons/ammo/etc. after changing maps, the map CFGs can also be used to give players appropriate equipment on appropriate maps (e.g., if on the first map, the players should have picked up an MP5 and lots of ammo, on the second map they could spawn with an MP5 and an amount of 9mm ammunition). Full info on the map CFG files is below.

New Features:

SvenCo-op v1.9/v2.0 contains several new entities and entity properties. For information on using these entities, check the Entity Guide! 

Using Map CFG Files:

You can set up various options in map CFG files, such as changing the player starting weapons/ammo/items, turning realistic falling damage on/off, disabling certain transitions, forcing a certain map to be run after the current map ends, etc. This is a powerful system and allows the mappers to set the rules of the game without a lot of entity usage. 

When a map is loaded in SvenCo-op, the game automatically tries to execute a CFG file with the same filename as the map (but ending in .cfg instead of .bsp). For example, if you ran a map called svencoop1.bsp, the game would try to execute a file called svencoop1.cfg. If no file of that name exists, default settings will be used (Players start with a crowbar, a pistol and other default settings). All CFG files must be in the SvenCoop\maps\ directory for them to be recognised...

To make a map CFG, go to the SvenCoop\maps\ directory, then make a copy of cfgtemplate.cfg. Rename it to whatever you want, and open it in a text editor (such as Notepad). 

The CFG template is fairly self-explanatory, there are comments explaining what each option does and how it affects the game. 

There is a problem however, where if a map uses a trigger_gravity entity, every time the config is loaded it resets the gravity to what is written in the file, so if the map uses a trigger_gravity, it may be best to remove the sv_gravity line in the config.

Here's a list of the starting equipment you can set... you can use as many commands as you like. Please note, however:

• Do not use the same command twice! Also, make sure that you don't use both weapon_uzi and _uziakimbo.
• Weapon_ commands must not have a number after them. 
• Ammo commands must have a number after them. The number is not the number of clips, but the actual number of rounds (e.g. ammo_9mm 2 would give players 2 bullets, not 2 clips). Amounts below are only examples.
• The akimbo Uzis are very powerful. It's wise to consider giving players a single Uzi rather than two... players will still be able to acquire Akimbo Uzis by picking up a second Uzi from a player's corpse.

Weapons:  weapon_crowbar  weapon_glock  weapon_shotgun  weapon_mp5  weapon_357  weapon_crossbow  weapon_hornetgun  weapon_rpg  weapon_gauss  weapon_egon  weapon_snark  weapon_handgrenade  weapon_tripmine  weapon_satchel  weapon_uzi  weapon_uziakimbo Ammo:  ammo_9mm 16  ammo_ARgrenades 2  ammo_buckshot 8  ammo_357 6  ammo_crossbow 5  ammo_rpgclip 1  ammo_gaussclip 10 Other:  item_longjump  nosuit (not recommended)

 

Do's and Don'ts of Sven Co-op Map Making:    * = Imperative

* Don't set the Max Live Children value on monstermakers too high (e.g. if you set it to 100, the monsters may crash the server if they're not killed constantly).

* Do Make it so that if a map has a objective, the map will end by use of a game_end after the map is finished, so players don't have to wait 'till the timelimit is hit.

* Don't rely on huge swarms of monsters to make the map more difficult. The more monsters there are in a map, the more laggy it will be. Try to find other ways of making the map difficult.

Do Remember that with Sven Co-op it is necessary to keep the R_speeds and amount of monsters on-screen down, no one likes a slow game.

Don't Place particularly large amounts of ammo and weapons around a player starting area, this can reduce framerates, and lead to fights and ammo hoarding. Instead, put most of the information into the config file, so the players can get straight into the action without waiting for the ammo and weapons to respawn.

Do try to force the players to work together, a good example of this is Crisis2 (released with 1.9) where the players work together at a number of points for their own benefit and to progress the map.

Don't rely on a Gimmick to support your map, most of the best Sven co-op maps are Walkthrough, and rarely stay in a single area all the way through the map. 

Do test the map to its fullest with a number of players, if there is something that can be exploited, you should find out about it now and not later.