ACR Encounter

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The ALFA Encounter System provides an easy means for builders to add terrain specific random encounters to module areas. The system is a collection of creatures, scripts, and waypoints, built on top of the ACR Spawn System, that allows a builder to easily add terrain appropriate random spawns. It is intended to be trivial to implement, and to decrease predictability for spawn groups in a given area.

The lowest logical unit is a creature. This is typically a single generic creature from an approved source such as Monsters of Faerun or the Monster Manual. You can spawn them individually in the DM Chooser for live play, but it is not recommended to use them within the toolset directly.

Above the creature is a creature group. A group is typically either a specific number of homogenous creatures, like a Kobold Gang EL 1 (1d6 + 3 kobolds), or a group of mixed creatures like an Orc Patrol EL 7 (1d4+4 orcs, 1d2 2nd level orc barbarians, and a 4th level orc leader). You can use these groups directly in your modules, but they can be predictable and subject to farming if the same group always spawns in the same place.

Above the creature group is a terrain group. A terrain group is a collection of creatures groups and single creatures appropriate for a given area. So for the Temperate Clear group, you might have a 10% chance of neutral animals, 10% militia patrol, 5% bandits, and so forth.

With a basic knowledge of scripting you can also use the predefined creature groups or terrain groups for your own custom areas, and you can modify or customize the scripts specifically for your server.


You will need to acquire the latest version of the ALFA Campaign Folder, or from a maintainer of the content. Within the campaign folder is a full set of ALFA compliant creatures, along with a set of scripts and waypoints to spawn then in intelligent groups.

You will need to associate the ALFA-Campaign folder with your module from within the Campaign Editor plugin, then save, then reload to associate them with your module.

First, choose an area and terrain in your module to populate. Most areas conform to a loose climate zone; three examples might be temperate plains, southern mountains, or dungeon. Pick a terrain and difficulty that makes sense to you (for instance, you might choose ALFA_Groups->Dungeon->Dungeon EL 1-3 or Dungeon 4-6 for the upper and lower layers of a low level cave). Builders often place lesser dangerous areas close to major roads and towns, where more difficult areas would be in more remote areas. A good mix also ensures there are areas for PC parties of various levels.

Next, decide how frequent you want the creatures to be. A general guideline is a small area should have 1 active, a medium 2, and a large area 4, but you can increase or decrease if you like. By default, each individual spawn waypoint is active 50% of the time, but this can be changed by editing the placed waypoint ACR_SPAWN_CHANCE variable. You may want to keep the PCs guessing by dropping a number of waypoints to sum to your desired probability (1x50% spawn is active half of the time, whereas 3x33% chances would mean one would be active on average at a given time, or 8x25% would mean 2 would be active on average, etc). The spawn waypoints will reroll a chance to be active every 3 hours or so, and if destroyed will delay between 1 and 3 real life hours before having a chance to reactivate.

Finally, place the waypoints. In the Blueprints section, navigate to ALFA_Groups, then pick from Environment or Hostile or Defender spawns. For example, a Temperate Clear area would be ALFA_Groups->Environment->Temperate->Clear EL 1-5. Drop your waypoints away from ATs in sensible locations, and adjust the probability for your spawn waypoints with the ACR_SPAWN_CHANCE as desired. When you restart the server, you should see your creatures start to spawn.

Current Groups

Each terrain type has a default difficulty range. The Encounter Level (EL) of a spawn is generally appropriate for a party of 4 PCs of that level, so an EL 5 would be appropriate for a group of 4 5th level PCs. For above ground terrains, the difficulty is often higher at night.

  • ALFA_Groups->Defender (adventurers, dwarven or elven teams, halfling scouts, merchants, etc)
  • ALFA_Groups->Dungeon-> Dungeon - EL 1-3
  • ALFA_Groups->Temperate>Temperate Clear (EL1-5)
  • ALFA_Groups->Temperate>Temperate Hills (EL 2-9)
  • ALFA_Groups->Hostile (Animals, constructs, humanoids, lycanthropes, etc)

Technical Notes

  • Click on any waypoint and see the description field to determine the number and type of creatures spawned for that waypoint
  • The waypoints use scripts defined in as_group_<name>. Examine the scripts to see how they are made
  • To create your own encounters, you can copy a waypoint, and edit the ACR_SPAWN_GROUP_1 variable to point to your custom script. Then, copy any existing group script and save it with the name as_group_<new group>. You can then call other groups with any probability, or add your own creatures into the mix.