Right. Well. I have it, I have read it, I haven't played it, but... Warrior is basically an update of WRG Ancients 7th Edition which I used to play a lot of but haven't played since about 1991.
My memory is weak so I will try to give a very basic explanation. I hope it will be better than nothing. Also I found some web links that may be useful.
Troop Types
Your army is divided into a number of units consisting of 1 or more elements containing troops of a single type, such as heavy infantry, knights, bowmen and so on.
The type of troops in a unit is defined by their armour class, morale/training class and weapons carried. The typical description is something like
HI,
Sh, HTW, Reg B which means Heavy Infantry, Shield, Heavy Throwing Weapons, Regular B morale which would describe a Roman legionary.
Units cannot be split and recombined.
Set Up
Before the game there is a scenario set up phase where you put down terrain, try for flank marches and other tings, for example it is possible to have a surprise night attack.
At the start of the game you write basic orders for each unit. These are something like Attack, Defend, Skimish and so on and they limit what your units can do.
Once the game starts you move your units within the limitation of their orders. It is a simultaneous movement system.
When you are close enough to the enemy you can shoot at them or charge. Charging requires a morale test. The unit charged at might be able to evade or countercharge.
Your generals can change orders during the game but they need to be close enough.
Fighting
To do casualties you look up the weapon vs target armour class, check the modifiers (flank attack and so on) and roll a die. This gives you a casualty number off a chart. The number of casualties is compared to the target's number of figures and elements and translated into fatigue points. You don't remove any figures. As a unit's fatigue points pile up, it becomes more vulnerable to bad morale effects and fights worse. For example, if your unit is on 5 fatigue it gets -1 die modifier in combat. Once it gets to 15 fatigue per figure (I think) it basically becomes useless and can easily be destroyed (removed from the table.)
Units also accumulate fatigue for charging and shooting. The shooting fatigue only affects theit performance in shooting and represents running out of ammo.
Big units suffer less fatigue from casualties but accumulate fatigue from shooting or charging at the standard rate.
Morale is important. Morale tests happen because of things like being charged, wanting to charge, seeing friends retreat and so on. Depending on the result of the morale test your unit might refuse to move or it might go impetuous. The unit morale class affects this of course. (You need "average" dice to do morale tests for regular troops.)
Tactics and Stuff
It is quite hard to destroy units so influencing morale is important. You can influence your own troops' morale by advancing, having an army banner and such like. Influence the enemy's by making his units retreat, flanking them and so on.
Be sensible about fighting. Don't send heavy knights in to chase light infantry. The knights will win but they will get fatigued. Light cavalry will do a better job. As with all wargames you win by getting match-ups in your favour, economising your force, outnumbering and flanking and other basic tactics.
Web Links that might help
http://www.fourhorsemenenterprises.com/history.htm
http://www.nasamw.org/warrior_resource_page.htm
http://theminiaturespage.com/rules/anc/wrga7.html
If you find you don't get on with Warrior, don't give up on Ancients. There are lots of other rules available.
