A friend of mine had a copy of Wizards, but we never played it because it had a lot of problems. Several of the rules seemed unclear, and the last part of the game (in which players who have achieved the highest possible rank must then chase down the High Wizards in search of Sacred Gems) seemed to take forever. Over time, my gaming group modified the rules a lot, and developed a version of the game that we consider a lot of fun. I'd estimate we still use about half the rules from the original game.
If you have a copy of the game and are interested in our changes (or if you don't but are curious anyway), here are our reference sheets, which incorporate all our changes (as PDF; click here for PostScript). The main sheet resembles the sheets that come with the game, except we don't use it for recording tasks or other such stuff that arises in play; we use it solely for reference. (We track durations of animals and events by placing markers on the Calendar track, and track tasks and points on scratch-paper.) Thus we were able to fit in a lot more information. The first two pages are designed to be used as a single two-sided reference sheet.
We've also produced some player aids: a version of the game mat with larger spaces to accommodate sleeved cards (including a separate smaller mat for the Task and Event cards), and a chart of the 11 tasks that can still be instantiated when the only remaining lands are the Sacred Circle and the Dragon's Lair, which can be useful when trying to draw a new Task during the "two-tile endgame".
One item may look like a change but isn't: the RANDOM WIZARDS table. This is just a way of saving wear and tear on the Wizard cards by using percentile dice (two 10-sided dice; use a white one and a colored one and read the white die first as usual) to select one of the 14 cards at random. If a Wizard or Secret Wizard marker is on the board you have to resort to shuffling the deck as before. (If the only markers are for non-secret Wizards, and no phantasm or trap cards have been removed from the deck with the Wizards, you can still roll the dice and then reroll as necessary.)
The reference sheets also include some information that is unchanged from the rules but which we found was needed often enough that it was worth having on the sheet: Random Encounters, the order things happen in if you have Multiple Specific Encounters, descriptions of the effects of Animals, etc. We also include rulings we've made when we found the printed rules to be unclear.
More recently, we developed rules for two new "character classes" in addition to the wizards, sorcerers, and druids of the original game. The new classes are described under ORDER OF RANGERS and ORDER OF EVIL, and the points requirements, new spells, and other details are incorporated into the rest of the pages. After refining those rules a while, we decided it was time to update the sheets posted here, and took the opportunity to reorganize the information quite a bit. That uncovered some places where our rules would be simpler if we made some small changes, plus we incorporated selected items from a page of suggestions posted by the game's original designers, Coral and Thomas Mosbø. The last (short) page lists the changes between this version and the 2002 version of our rules (PostScript).