Weird War II is a fine example of how the d20 system can be used to create an RPG outside of the fantasy/D&D genre. The setting for Weird War II is, predictably, the Second World War.

This first book in the Weird War series for the d20 System provides the reader with material to run a game on the western European front just after D-Day. This setting uses the Nazis as the embodiment of evil and the players take part in the war against Germany. The idea is that the characters will begin play with a position in one of the allied armies, as a soldier, officer or medic. Characters can also be a member of the resistance. The first few games will likely consist of skirmishes against German troops. Then things should get weird.

The underlying tone of the setting is one of horror/conspiracy. This is how the story goes:

The Nazis, and the Thule society before them, have uncovered ancient secrets from archeological digs around the world. The most important discovery was that of the Elder Futhark, the ancient Germanic runes. These can be used to cast spells, and most SS officers are trained as Mages. The Nazis have discovered that by channeling the energies of death, violence and suffering, their magic can be enhanced. As a result, they have constructed death camps for the purpose of powering their magic.

The Nazis have also captured a Russian werewolf and have implemented a breeding program with the intention of creating werewolf battalions.
In the world of Weird Wars, dark energies are released when there is warfare. Those energies spawn monsters, such as the living dead. Spirits of the dead haunt battlegrounds and occasionally animate vehicles. The Nazis are not the only ones who are aware of this fact.

A secret organization called the OSI has been watching the world for millennia. Their goal is to keep humanity unaware of the occult and to eliminate any possibility of that information being disseminated, the end justifying the means. Top ranking OSI are afraid that Hitler is "the beast" of their prophecies, the one whose evil power is sufficient to destroy the world. The OSI have also learned the secret of the runes and they have educated adepts in their uses to oppose SS officers.

Characters who become aware of the supernatural and survive encounters with it will very likely be approached by OSI agents at some point. They may be taught the use of runes. Knowledge is dangerous though. Once the OSI does not need those adepts anymore it might consider them living proof of the supernatural and find it best to remove them from the face of the world…

New rules: Included are rules on the uses of firearms, flame-throwers, artillery, mines, and vehicle combat (tanks). The character classes described are the Grunt (equivalent of the Fighter), the Officer (holds rank and can command soldiers), the Medic (can use medical skills to heal characters), the Resistance Fighter (equivalent of the Rogue) and the Scout (a mixture of Rogue and Ranger). The military prestige classes are the Commando and the Sniper. The OSI prestige classes are the OSI chaplain (uses the new Prayer skill to cast priest spells or "miracles"), the OSI Adept (uses the new Rune Magic system) and the OSI Operative (an assassin).

Magic is treated in a new way. Some spells are gone from the list (no wizards running around and using lighting bolts and fireballs to blow up hordes of enemies - for that, use hand grenades). Adepts have to know the runes needed to cast a specific spell. Casting a spell requires a Spellcraft or Prayer check and causes subdual damage to the caster because of fatigue. Magic items can be created by inscribing runes upon them.

Weaknesses: All in all, this book delivers what it is supposed to. There are a few typos and one table seems to be missing (the Decoration Table to award medals).