1. Using commands and building stuff

In this lesson, we will test out what we can do in-game out-of-the-box. Evennia ships with around 90 default commands, and while you can override those as you please, the defaults can be quite useful.

Connect and log into your new game and you will end up in the “Limbo” location. This is the only room in the game at this point. Let’s explore the commands a little.

The default commands has syntax similar to MUX:

 command[/switch/switch...] [arguments ...]

An example would be

 create/drop box

A /switch is a special, optional flag to the command to make it behave differently. It is always put directly after the command name, and begins with a forward slash (/). The arguments are one or more inputs to the commands. It’s common to use an equal sign (=) when assigning something to an object.

Are you used to commands starting with @, like @create? That will work too. Evennia simply ignores the preceeding @.

1.1. Getting help

help

Will give you a list of all commands available to you. Use

help <commandname>

to see the in-game help for that command.

1.2. Looking around

The most common comman is

look

This will show you the description of the current location. l is an alias.

When targeting objects in commands, you have two special labels you can use, here for the current room or me/self to point back to yourself. So

look me

will give you your own description. look here is, in this case, the same as plain look.

1.3. Stepping Down From Godhood

If you just installed Evennia, your very first player account is called user #1, also known as the superuser or god user. This user is very powerful, so powerful that it will override many game restrictions (such as locks). This can be useful, but it also hides some functionality that you might want to test.

To temporarily step down from your superuser position, you can use the quell command in-game:

quell

This will make you start using the permission of your current character’s level instead of your superuser level. If you didn’t change any settings, your game Character should have an Developer level permission - high as can be without bypassing locks like the superuser does. This will work fine for the examples on this page. Use

unquell

to get superuser status again when you are done.

1.4. Creating an Object

Basic objects can be anything – swords, flowers, and non-player characters. They are created using the create command:

create box

This created a new ‘box’ (of the default object type) in your inventory. Use the command inventory (or i) to see it. Now, ‘box’ is a rather short name, let’s rename it and tack on a few aliases.

name box = very large box;box;very;crate

Warning

MUD clients and semi-colon: Some traditional MUD clients use the semi-colon ; to separate client inputs. If so, the above line will give an error. You need to change your client to use another command-separator or to put it in ‘verbatim’ mode. If you still have trouble, use the Evennia web client instead.

We now renamed the box to very large box (and this is what we will see when looking at it), but we will also recognize it by any of the other names we give - like crate or simply box as before. We could have given these aliases directly after the name in the create command. This is true for all creation commands - you can always tag on a list of ;-separated aliases to the name of your new object. If you had wanted to not change the name itself, but to only add aliases, you could have used the alias command.

We are currently carrying the box. Let’s drop it (there is also a shortcut to create and drop in one go by using the /drop switch, for example create/drop box).

drop box

Hey presto - there it is on the ground, in all its normality.

examine box

This will show some technical details about the box object. For now we will ignore what this information means.

Try to look at the box to see the (default) description.

look box
You see nothing special.

The description you get is not very exciting. Let’s add some flavor.

desc box = This is a large and very heavy box.

If you try the get command, we will pick up the box. So far so good, but if we really want this to be a large and heavy box, people should not be able to run off with it that easily. To prevent this we need to lock it down. This is done by assigning a Lock to it. Make sure the box was dropped in the room, then try this:

lock box = get:false()

Locks represent a rather big topic, but for now that will do what we want. This will lock the box so noone can lift it. The exception is superusers, they override all locks and will pick it up anyway. Make sure you are quelling your superuser powers and try to get the box now:

> get box
You can't get that.

Think this default error message looks dull? The get command looks for an Attribute named get_err_msg for returning a nicer error messageod (this can be seen from the default get command code). You set attributes using the set command:

set box/get_err_msg = It's way too heavy for you to lift.

Try to get it now and you should see a nicer error message echoed back to you. To see what this message string is in the future, you can use ‘examine.’

examine box/get_err_msg

Examine will return the value of attributes, including color codes. examine here/desc would return the raw description of your current room (including color codes), so that you can copy-and-paste to set its description to something else.

You create new Commands (or modify existing ones) in Python outside the game. We will get to that later, in the Commands tutorial.

1.5. Get a Personality

Scripts are powerful out-of-character objects useful for many “under the hood” things. One of their optional abilities is to do things on a timer. To try out a first script, let’s put one on ourselves. There is an example script in evennia/contrib/tutorials/bodyfunctions/bodyfunctions.py that is called BodyFunctions. To add this to us we will use the script command:

script self = tutorials.bodyfunctions.BodyFunctions

This string will tell Evennia to dig up the Python code at the place we indicate. It already knows to look in the contrib/ folder, so we don’t have to give the full path.

Note also how we use . instead of / (or \ on Windows). This is a so-called “Python path”. In a Python-path, > you separate the parts of the path with . and skip the .py file-ending. Importantly, it also allows you to point to Python code inside files, like the BodyFunctions class inside bodyfunctions.py (we’ll get to classes later). These “Python-paths” are used extensively throughout Evennia.

Wait a while and you will notice yourself starting making random observations …

script self

This will show details about scripts on yourself (also examine works). You will see how long it is until it “fires” next. Don’t be alarmed if nothing happens when the countdown reaches zero - this particular script has a randomizer to determine if it will say something or not. So you will not see output every time it fires.

When you are tired of your character’s “insights”, kill the script with

script/stop self = tutorials.bodyfunctions.BodyFunctions

You create your own scripts in Python, outside the game; the path you give to script is literally the Python path to your script file. The Scripts page explains more details.

1.6. Pushing Your Buttons

If we get back to the box we made, there is only so much fun you can have with it at this point. It’s just a dumb generic object. If you renamed it to stone and changed its description, noone would be the wiser. However, with the combined use of custom Typeclasses, Scripts and object-based Commands, you could expand it and other items to be as unique, complex and interactive as you want.

Let’s take an example. So far we have only created objects that use the default object typeclass named simply Object. Let’s create an object that is a little more interesting. Under evennia/contrib/tutorials there is a module red_button.py. It contains the enigmatic RedButton class.

Let’s make us one of those!

create/drop button:tutorials.red_button.RedButton

The same way we did with the Script Earler, we specify a “Python-path” to the Python code we want Evennia to use for creating the object. There you go - one red button.

The RedButton is an example object intended to show off a few of Evennia’s features. You will find that the Typeclass and Commands controlling it are inside evennia/contrib/tutorials/red_button

If you wait for a while (make sure you dropped it!) the button will blink invitingly.

Why don’t you try to push it …?

Surely a big red button is meant to be pushed.

You know you want to.

Warning

Don’t press the invitingly blinking red button.

1.7. Making Yourself a House

The main command for shaping the game world is dig. For example, if you are standing in Limbo, you can dig a route to your new house location like this:

dig house = large red door;door;in,to the outside;out

This will create a new room named ‘house’. Spaces at the start/end of names and aliases are ignored so you could put more air if you wanted. This call will directly create an exit from your current location named ‘large red door’ and a corresponding exit named ‘to the outside’ in the house room leading back to Limbo. We also define a few aliases to those exits, so people don’t have to write the full thing all the time.

If you wanted to use normal compass directions (north, west, southwest etc), you could do that with dig too. But Evennia also has a limited version of dig that helps for compass directions (and also up/down and in/out). It’s called tunnel:

tunnel sw = cliff

This will create a new room “cliff” with an exit “southwest” leading there and a path “northeast” leading back from the cliff to your current location.

You can create new exits from where you are, using the open command:

open north;n = house

This opens an exit north (with an alias n) to the previously created room house.

If you have many rooms named house you will get a list of matches and have to select which one you want to link to.

Follow the north exit to your ‘house’ or teleport to it:

north

or:

teleport house

To manually open an exit back to Limbo (if you didn’t do so with the dig command):

open door = limbo

(You can also us the #dbref of limbo, which you can find by using examine here when in limbo).

1.8. Reshuffling the World

You can find things using the find command. Assuming you are back at Limbo, let’s teleport the large box to our house.

teleport box = house
    very large box is leaving Limbo, heading for house.
    Teleported very large box -> house.

We can still find the box by using find:

find box
    One Match(#1-#8):
    very large box(#8) - src.objects.objects.Object

Knowing the #dbref of the box (#8 in this example), you can grab the box and get it back here without actually yourself going to house first:

teleport #8 = here

As mentioned, here is an alias for ‘your current location’. The box should now be back in Limbo with you. We are getting tired of the box. Let’s destroy it.

destroy box

It will ask you for confirmation. Once you give it, the box will be gone.

You can destroy many objects in one go by giving a comma-separated list of objects (or a range of #dbrefs, if they are not in the same location) to the command.

1.9. Adding a Help Entry

The Command-help is something you modify in Python code. We’ll get to that when we get to how to add Commands. But you can also add regular help entries, for example to explain something about the history of your game world:

sethelp History = At the dawn of time ...

You will now find your new History entry in the help list and read your help-text with help History.

1.10. Adding a World

After this brief introduction to building and using in-game commands you may be ready to see a more fleshed-out example. Evennia comes with a tutorial world for you to explore. We will try that out in the next lesson.