Warcraft is a combination of abilities for the Knightly profession, primarily the art of poison lore and trapping. Poisons grow all over Avalon, and when you learn to recognise one, you may ANALYSE it, PICK it and then PREPARE it. A most useful ability for populating your trusy blade with a little extra bite. Once you have attained the Knight profession fully you will also be able to use your Warcraft to PLANT various poisons.
Trapping is also a worthwhile pursuit; you will be able to PREPARE a trap, providing you have the correct components, and then LAY it in a specific direction to affect your enemies. By divine edict traps are not particularly effective against the very young of the land.
IMPORTANT INFO FOR MEMBERS OF THE KNIGHT PROFESSION
It may be that you have Warcraft or Trapping (or, under certain extraordinary circumstances, a singular fourth skill) and decide to move to a guild (within the same profession, thus no CHANGE PROFESSION is used) with a different fourth core skill. By default you will retain the original fourth guildskill, from your first knight profession guild, without any change in its level or any restrictions on its continued development. You will, however, NOT gain access to the new fourth core skill from the new guild standards. This may suit you and you can continue to freely work up your original fourth skill as normal; but you have the option, although costly, of switching over to develop the new guild's fourth core skill.
In order to gain access to the new guild's fourth core skill you will need to surrender in its ENTIRETY the previous guild's fourth; effectively losing everything you had poured into its development. This is a major decision and should not be taken lightly. If you elect to make the change, your previous fourth (Trapping, Warcraft, etc) will be lost to your forever and you will gain the new guild's fourth core skill at 'Beginner' level. You will of course be free, subsequent to the changeover, to learn/develop your new fourth skill to the fullest extent possible - just as if you had begun with it from your very first apprenticeship.
To make this momentous change type SURRENDER followed by the coreskill you currently have on your SKILLS list, e..g. SURRENDER WARCRAFT, SURRENDER TRAPPING or SURRENDER <fourth skill-name>. You will get an opportunity to confirm your choice and - if you do so - the deed will be done instantly; your skills will change forever and the new guild's fourth specialist skill will appear on your SKILLS list at 'Beginner' level. All of this applies only to members of the knight profession.