The easiest word to describe Garry's Mod (gmod from now on) is to call it a sandbox. Originally it was developed by Garry
Newman (thus the name) as he wanted to try out the physics engine capabilities of the Havoc Engine which is used the game
engine Source Engine. In the end Garry's Mod has kinda developed into a big nowadays even commercial game modification. The
main focus has barely changed: Garry's Mod is intended to give its users freedom when it comes to whatever they like to do
with the Source engine - if it is writing special scripts, making so-called ragdolls (which will be the main topic when
we're going into the GTS theme) or making computer-controlled NPCs.. it's up to the user. Thus nowadays Garry Newman is mainly
at work at allowing more possibilities for the user to achieve - rather than writing tools the player in the end uses
himself.
You might say.. he hands you the tools and you do whatever you like with them. As to its nature and admitted fact that the
"normal" user only wants to use finished stuff rather than doing everything from scratch a community around that
game has developed where user-made content is shared among users.
I hope you agree that a video normally speak better than thousand words: thus this is the official Garry's Mod trailer which
has been used on its store page until end of 2008:
Additional ressources to get Garry's Mod informations are:
There are two options nowadays.. there is a version of Garry's Mod which is free and one which costs $9.99/9.99€/£5.99 (prices are subject to change). However the free version isn't truely free: the free version requires you to have 3 Source engine driven games. These are:
These three games are urgently required for the "freeware" version. Additional the freeware version is unsupported nowadays, most new content will simply not run on it. The commercial version goes down a different path. It requires you to have on Source based game by VALVe.. possible games as of March 2009 are:
* - availible in a bundle: Garry's Mod + that game for a cheaper price ** - While Left 4 Dead works, you'll literally have no content in Garry's Mod
Just to repeat. You only need one of the games on that list (PC version only however). Then you can buy the commercial version. If you go the cheap way and only get like Half Life 2: Deathmatch ($4.99 as of now) you'll certainly be much cheaper than with the "freeware" version. You can get all these games online at the offical Steam store (download games then) or via resellers such as Amazon or your public market. Garry's Mod however can only be bought online, there is no other way, you will therefore require to be able to pay online (credit card, PayPal or country dependent options). The easiest way if you do not have any of these games yet is to download Steam from steampowered.com and create a personal Steam account first (needed but it's pretty much straight forward). Once you're greated by the Steam interface the first tab (Store) is going to be selected. In the search box type in Garry's Mod and it will quickly bring you to the Garry's Mod buy page:

You see it is also showing you all availible bundles to buy. Please note that if you're going for other games to bundle
up - that's up to your choice. And always check game bundles.. several bundles such as the Orange Box (includes Half Life 2,
HL2 Episode 1, Episode 2, Portal and Team Fortress 2) would allow for quite cheaper buying options.
For getting the
"freeware" version: while it's still floating around you will have to google for stuff like "GMod9
download" however in that guide it won't be covered much further. That version was just basically covered because I
know about too many people always screaming "You're telling us to pay money, there's a freeware version" - as
mentioned in case you're only interested in Gmod and no other interest about the Source driven games then you'll most likely
end up cheaper taking the commercial version, therefore the quotations for the "freeware" version. It simply is no
real freeware in my eyes!
One last note: the system requirements are not too high. A decent PC from 5 years ago will most likely be able to handle
it. My notebook which is 3 years old and crappy when it comes to modern games easily manages it so nowadays PCs and laptops
should handle it. The important aspect.. you should have a proper graphics card and no onboard solutions or such.. if you look
into your device manager and your display adapter shows up something like ATI, Radeon, Nvidia, Geforce then it'll most likely
work. Typical onboard deviced (intel accelerated blabla) can get into troubles however. If you're unsure: download the demo
of Portal: First Slice - this games use the same engine as Garry's Mod. If it runs fine then GMod will surely work! The
official requirements are:
Minimum: 1.7 GHz Processor, 512MB RAM, DirectX® 8 level Graphics Card, Windows® Vista/XP/2000, Mouse, Keyboard,
Internet Connection
Recommended: Pentium 4 processor (3.0GHz, or better), 1GB RAM, DirectX® 9 level Graphics Card, Windows® Vista/XP/2000, Mouse,
Keyboard, Internet Connection
Jeeze, answering that will result in an endless wall of text. GMod is intended to allow endless possibilites.. stuff not possible will be made possible by users.. that's kinda about it. What I'd recommend you: there is a tutorials section in the main menu. It covers three core points about the game including one most GTS lovers will probably end up using. The three tutorials are:
Other than that.. I really am sorry to say.. there's too much to be written. It's really endless! Visit the official forums in that case or try playing around yourself - I btw recommend the second it's much more fun to try out and fail all the time!
I was always mentioning it.. endless possibility. And endless certainly includes GTS content. However, many might wonder "How can I get a STool to enlarge models" (STool = Tool for the spawn menu). Unfortunately it is not that easy, the reason is technical and I want to short it down: the Source Engine simply does not allow proper resizing of models in real time. It simply does not work, there were multiple tries before! So well.. we have to do it the other way!
In some cases you will be able to find pre-resized giant models on the Garry's Mod official download page. Searching might be a little complicated but there exist quite a few models:

There is also a trick to make models appear larger. That is the following: VALVe cheated when it came to make maps you play on look large. Their trick was.. there is a hidden skybox area of each map.. that skybox area is linked to the area you actually play on and it's seemingly connected. Truth is.. the Skybox is shrunk.. by factor 16. The game enlarges it in real-time so that it appears normal-sized for you! However.. as GMod allows you to fly through walls and also through areas not belonging to the map (press V to switch into noclip mode and back) you can search the skybox:

So.. let's search the skybox on this map!
So let's start
noclipping!

That's the transition.. quite visible but imagine.. when gaming usually you
never come as close as that to it!

Noclipping out - and we can see the map from outside.. now we have to fly
around to search the skybox.

Aha.. that must be it.. let's fly there!

Isn't that the scene we saw from the inner just a few moments ago? Looks
like toy trains now. Let's put a model here!

Not my best pose.. but anyway.. she sure looks larger than the trains.
Let's try flying back to the map - back to the transition of the skybox!

Okay, from below the pose looks even more messed up *lol* - but anyway:
the game connects the skybox with the rest.. the skybox gets enlarged by factor 16.. and there she is!
The skybox trick has advantages and disadvantages.. one advantage is its easiness.. it works on all maps having a skybox and it works with absolutely all models out there. It won't fail a single time, I promise that much. However one disadvantage is that your growth factor is really limited to 16 (at least on all VALVe maps, some maps use different but no major differences are to be expected here). Additionally.. if you like to get closer to the model. It simply won't work as the model is not part of the actual map.. touching the model is impossible and trying to get some interaction scenes working is really hard to perform and most likely requires multiplayer where you command another player like "Head must look more down", "Eyes look wrong" and more. Simply because the result of the skybox pose can only be seen in the actual map area, posing however is only possible in the skybox. In worst case you'll need to set up several cameras (you can switch to the viewport of a camera by pressing a button on your numpad) just to check if things look right. However.. it is still a fun way to work with and as mentioned it's easy. Because finding the skybox really isn't hard in normal cases (I never tried it on the map used in the screenshots above and I took like 20 seconds to spot it) - simply fly way up over the map and look around.. if there's no skymap visible fly under the map. It has to be somewhere ;)!
The player resizer is a so-called STool (Spawnlist Tool) which has recently been added to GMod which is also a quite easy trick to get at least GTS impressions. Again models are not actually resized but you as a player can get the impression they'd be resized. Click here to download the Player resizer from its original location! Unpack the ZIP file into [steam]\steamapps\[your steam name]\garrysmod\garrysmod\addons.
Now you can launch GMod. In the tool menu on the right side you'll now see new menu points:

The player resizer resides here!

Select the wish scale on the right screen half - we select 16 for this!

Now just some right-clicking according to instructions!

Now that's a difference!
And it also works the other way around!

Amy Rose model to human model - as a Sonic character she's normally much smaller than human models!

Now first-person view just to stretch that statement!
Now let's select the player resizer and go down to 0.2!

The crowbar won't help you far, Barney!

First person again!
The skybox trick has its limitations.. but all these limitations can be avoided by resizing actual models. Yes, that works. However, this part is tricky and truly requires an in-depth guide. However.. such a guide exists.. written by me and originally it was for resizing a Rouge (Sonic the Hedgehog) model which was kinda small in comparison to all other Sonic models released as of now. Get to an adjusted version of the guide here!
Some notes about that method: (feel free to read the guide first, you'll get
redirected here once you're done.)
In comparison to the skybox method that method has the clear advantage that the model
is actually resized including everything with it. Therefore these models CAN be used directly next to other models and they
can even touch other models. Interaction is thus MUCH easier. It is also possible to go the mini GTS way, planetary GTS
(there are indeed planet maps) and whatever way you like - it's all possible and up to you. It has two disadvantages however:
one is that the steps required to do it are much harder to learn.. and unfortunately the Source Engine gets in trouble when
it comes to face flexes (for face posing).. for big models those will most likely fail working or stretch the face into
totally unhealthy expressions. All in all, the method is still the preferred one in most cases! Typical example could be:

Impossible with skybox method.. just "only" double scale.. direct interaction with objects even holding another
model, the Skybox method will not allow this at all.

Same again.. no mini-gts however, but direct contact you might wanna say!
Which method should I use? Skybox, download or self-resize?
Up to you.. the download offers unfortunately are very small.
I do not get the self-resize method to work, can you help me?
Yes, I happily always, feel free to get into contact with me (Link, or link00y on Yahoo via VGGTS3 or via mail at:
link 0 x [at] gmx [dot] org (please remove spaces and replace [at] and [dot] the way it should be useful). In case you
choose the Yahoo group, I'll directly answer via e-mail to not spam the group.
Why don't we make a download central for pre-resized models like on the groups?
That's a little tough actually.. most porters dislike if people play too much with their models (although on a legel side
they still do not own them as they didn't model them). Many of them however do not care if their names are credited so
something like (model ported by X, rescaled by me) is okay.. I actually have never seen a modeller go totally insane as long
as people perfectly credited him. There still should be the option however to allow a porter to complain that something is
his model and he does not agree. Noone likes stealing but everything else.. normally goes okay. I repeat: I never saw a
porter going out of control because of recolors etc. as long as he was credited!
I wonder.. I resized models using the self-resize method but they do not appear in the spawn menu.
The self-resize method does not generate spawn menus.. you'll most likely have to select the browse tab in the upper right
of the spawn menu and manually browse to the models. If you compiled to soemthing like gtssamus\samus then you can click on
Garry's Mod\gtssamus and the spawn list will appear with all sizes you compiled. The models will be names samus001.mdl
(for normal size) or samus100.mdl (for 100 times larger).
My game seems to be locking up when I spawn a resized model!
The model is too big! 250 is kinda maximum scale possible. You can try a little above that but once a model is larger than the
allowed map size the game will freeze up.
Tiny models are unposable!
Known source engine problem.. but easily fixable.. look around for so-called rat maps.. these are maps where you as a player
are shrunken.. meaning the whole environment around you is technically enlarged.. thus normal sized models will look tiny
while large models look normal. That's the best workaround as of now.
How the heck do I get the Zero Suit Samus model working!?
The popular Zero Suit Samus model is tricky to install, as evidenced by the
several e-mails either Cubed or Link have gotten. A mini-guide on
getting it installed (along with downloads) can be seen here.
I do not claim ownership for the used Rouge, Fox, Krystal and Samus models for demonstration (original models by SEGA™/Sonicteam in case of Rouge/Amy, Valve in case of Barney, Nintendo in case of all others, ports by Unknown, nexus_elite, fluxMage or mario_kart64n), Garry's Mod is ©Team Garry, the Source Engine, the Source SDK, Half-Life and related are ©VALVe!