What is this?

Good question. This is a simple implementation of Goal-Oriented Action Planning (G.O.A.P.) in JavaScript.

What can I do with this?

If you're making a game with NPC characters that you want to appear realistic and smart, the GOAP can be a great option.

Example

Given the following world state, goals and actions:

export const worldState = {
  axe_available: true,
  player: {
    axe_equipped: false,
    wood: 0
  }
};

export const actions = {
  chopWood: {
    condition: s => s.player.axe_equipped,
    effect: s => {
      s.player.wood++;
      return s;
    },
    cost: s => 2
  },
  getAxe: {
    condition: s => !s.player.axe_equipped && s.axe_available,
    effect: s => {
      s.player.axe_equipped = true;
      return s;
    },
    cost: s => 2
  },
  gatherWood: {
    condition: s => true,
    effect: s => {
      s.player.wood++;
      return s;
    },
    cost: s => 5
  }
};

export const goals = {
  collectWood: {
    label: "Collect Wood",
    validate: (prevState, nextState) => {
      return nextState.player.wood > prevState.player.wood;
    }
  }
};

The GOAP Planner will create the following plan:

{
  "cost": 4,
  "goal": {
    "label": "Collect Wood"
  },
  "actions": [
    "getAxe",
    "chopWood"
  ]
}

For a more complex example, see Sim 2.

Further reading

Check out the following resource:

• FACING YOUR F.E.A.R
• Goal Oriented Action Planning for a Smarter AI
• Goal-Oriented Action Planning

Running the code

1. Install the dependencies npm init or yarn
2. Run the test npm run test or yarn test