WHAT YOU SHOULD KNOW: I feel very bad about this one, because I was asked to review this quite a while back, apparently misplaced the file, and have let WAY too much time go by without touching it. Altus Adventum is isn't a retroclone, but it is an attempt at recapturing earlier experiences with fantasy RPGs. The primer is a very meaty 92 page document that covers character generation, combat, skills and even a selection of monsters. Literally everything you need for at least an adventure or two is right here, completely free. The races are fantasy standards (human, elf, dwarf, halfling, gnome) with six attributes (Strength, Agility, Endurance, Intllect, Willpower and Luck) that run a range of 1-100. Combat uses dice pools in which each side compares the highest die in their pools for success. Magic is also included in this primer, with nine different forms to choose from, all operating off of the same basic mechanic, but with tweaks for the type you use. The monsters included cover basic animals as well as orcs, red caps, carnivorous plants and plenty more.
WHAT WORKS: For a free product, this primer has a ton of usable material in it. I mean, we're talking more than some smaller commercial PDF releases. I'm not sure what's missing from the main core book, but it is 204 pages, so presumably there is quite a bit extra there above and beyond the impressive amount of material here.
WHAT DOESN'T WORK: If you've gotten used to RPGs that tend towards using unified mechanics, Altus Adventum's different approach to combat versus skill checks is going to annoy you.
CONCLUSION: Look, I can't complain much about an incredibly complete free product. The primer covers all the rules you need to play, including skills, combat and magic, and even includes a decent amount of setting material, monsters and magical items. If you have any interest in checking out an another fantasy RPG, you have no reason not to at least download the primer...there is ample material here to decide if the full game is worth your purchase or not.
[5 of 5 Stars!]