There is a tick that allows you to join both the guards and the fire mages.
I took the text from this guide:
http://db.gamefaqs.com/computer/doswin/file/gothic_a.txt "* The quickest way to become a mage is to join the
firemages in the old camp, if you do, you can switch
to watermages later on."
"Getting the most out of the first Chapter
-----------------------------------------
* NOTE *
I would reccomend saving as many skillpoints you can during your
journey through this part of the walkthrough. If you do, and then
save before selecting your camp you will have a very nice save
to continue on when you want to replay the game
(testing other camps/classes) without having to remake the boring
part. You should be able to do most of this with only spending
about 10-20 skillpoints, or not even that...
* END OF NOTE *
1. Old Camp
Go to Old Camp
Speak to everyone, tell Diego you'd like to join and do
everything you can except the following:
- Dont do Thorus Mission without reading "2"
- Dont follow the Baal at the campfire (read on)
- Do Diego's "Test of Faith" if you wish, but DONT give Diego the
list (read on). The best thing of going to the mine so early in the
game is to get the bow (see the tips above).
2. New Camp
Convince Thorus that you are skilled enough to do him a favor.
When you get Thorus mission:
- Dont kill Mordrag, instead warn him about his danger.
Then follow Mordrag to the new camp.
On the way you will meet Cavalorn (Fingers told you about him).
Learn sneak if you have skillpoints (10 points).
To be honest, a rather useless ability, but required to get Fingers vote.
In the new camp - do everything you can. Solve all the quests you can.
Tell them you'd like to join... Talk to everyone.
When you only have the "must betray old camp" left to do,
you can go back to the old camp.
3. Sect Camp
Now find the Baal at the Campfire. Follow the Baal to the Sect Camp.
There, tell them you'd like to join. Do everything you can there,
get all Baals votes. Also make sure to picklock Cor Khalam's left chest
and grab his reicipe (you can do this while his helper is asleep at night).
When you CAN (dont do it now) join the Sect, you are done here.
4. The choice
* NOTE *
I would reccomend to do a MAJOR save here, since it will let
you replay the game without doing the *REALLY BORING STUFF* again.
Specially if you have saved lots of skillpoints.
* END OF NOTE *
Ok, so we have the Old Camp with a load of guards that abuse their
rights as much as they can and force people to work for them (blackmail).
We have the New Camp with a load of anarch bullies and a unforgiving
rice lord that is forcing the people to become slaves for him.
We have the sect camp with a bunch of weed smoking religious whackos...
What would you like to join?
Your choice doesnt matter, unless you would like to play as a Mage (see above).
The advantages/disadvantages of each camp wont affect you much.
Join what you feel for.
You will find out sooner or later who the "good" ones are anyway."
"Guard!
If you have joined the Old City, you can now report to Thorus to be
promoted as a guard. As a guard you can get a updated armor from Stone,
Learn 2-handed combat from Thorus, Crossbow from Scorpio
and buy things from Skip.
Ask if you can become a fire mage first, then end the conversation.
Now go straight to Coristo, the head fire mage, and talk to him.
(If you became a guard before speaking to Coristo, you will never get
the option to become a fire mage!) Say you want to be a fire mage,
take his test, then let him go up the stairs, and DON'T follow.
Go back to Torus _now_ and say you want to be a guard.
Get your guard armour, train whatever guard skills you want (like crossbows)...
No you can change your mind any time you wish and still become a fire mage!
(go back to Coristo on the upper floor with the pentagram to become a Fire
Mage)"
