Wizards of the Coast is going to offer Free Basic D&D; there are a number of D&D-like games out there that offer a Basic Set for free. Here’s a list for you:
Pars Fortuna
This RPG began as a fun experiment for it’s author and ended
up a playable and unique variant of
Swords & Wizardry with a unique set of player class/races, a whole caboodle
of new monsters, a comprehensive spell list with a variant magic system, and a
variety of interesting magic items. The Basic Set definetly gives you enough to
explain the rules and get the apetite going for wanting more (not needing more).
Spellcraft and Swordplay
An introductory version of spellcraft and swordplay for
levels 1 to 3. Enough to get you started on this variant on the classic.
Blueholme
This is a fantasy RPG builds itself on a foundation set by
the rules and flavor of the original basic rules for the most famous RPG in
history.
The publishers website: http://dreamscapedesign.net/category/blueholme/
The Blue Holme Prentice Rules for for levels 1 to 3, it’s
pay what you want so you can get it for free or chip in a couple bucks if you wish:
http://rpg.drivethrustuff.com/product/109409/BLUEHOLME-Prentice-Rules
Free/or Cheap and not just Basic (forgot to mention them last time):
Crumbling Epoch
As the author says it’s a pretty simple game with 12 pages
of rules. It offers a new and clever spin on familiar themes with a different
combat and magic system from the norm. Everything is laid out simply and a
veteran can come to grips on the whole thing with a careful reading.
Delving Deeper
A rehash of the original rules avialble in pdf for free as a
bundle or a separate download of each booklet.
Dangers and Dweomers
The autho’s personal spin on D&D.
Dark Dungeons
A comprehensive retro-clone that emulates the cyclopedia
version of D&D. The pdf clocks in at well over 300 pages and covers pretty
much everything you are going to need in an D&D-like RPG.
Flying Swordsmen RPG
Fantays marital arts in a variant D&D rule set that does
wuxia action well.
Microlite20
A whole collection of rule set to play fantasy RPG with
minor tweaks to emulate specific older versions of the game.
Searchers of the
Unkown
The original searchers of the unknown (and all it’s offspring)
are very minimal versions of fantasy RPG, all the rules in a page (or a maybe a
couple extra). A very easy means for people who have played RPGS before to play
with a few casual friends as 1 page of rules isn’t very intimidating.
There’s a bundle of different rules sets here:
http://www.retroroleplaying.com/content/searchers-unknown-rpg-collection