This article takes something of a break from the normal fare of interesting army variants and indispensable FAQs to bring you rules and background for using some of the more combatant fauna to be found in the Warhammer 40,000 universe. The reason for doing this is simple; we believe that we're all guilty of focusing on what's 'official' and usable in tournaments, sometimes at the expense of what's just good clean fun. Such rules as these formed the mainstay of Rogue Trader, the first edition of Warhammer 40,000, and as we all fondly recall many of the more wacky rules from those days we thought it might be fun to revisit some of them in Chapter Approved, 21st century-style.

Mike McVey's stunning diorama featuring a xenos riding beast.

Some of these rules are essentially 'random encounters'– creatures that pop up during a normal game and cause all manner of mayhem. Graham's Crotalids and Andy Hoare's Barking Toad are both good examples of this. You'll need to agree with your opponent well before the game that this is the sort of battle you're after, and play it in that spirit. Phil's Giant Reptiles introduce a new unit type into your army, which provides a cool modelling project as much as an opportunity to field an unusual unit every once in a while. Pete has taken the opportunity to provide Imperial Guard players with a new Regimental Doctrine, one of many he has squirreled away for future use after his work on Codex: Imperial Guard.

Andy Chambers' Enslavers and Mat's Catachan Devils rules are something else again – unusual projects for modellers and gamers that fancy a challenge.

We had enormous fun writing these rules, and there are a whole load more ideas we discussed that we ended up leaving out, often because of the difficulty of suggesting modelling options (Ambulls for example). However, if there's the demand for it we may revisit the Creature Feature in the future. We'd also like to encourage players to write their own rules for such creatures, and although you obviously don't need our blessing to use them in your own games, we'd be interested to see what you've come up with, and perhaps may include some in a future Chapter Approved.

One last word on these rules. It goes without saying that they all require your opponent's consent and are optional. Players should agree whether any of these rules are to be used, and in this sense they are ideal for use in a campaign. Even in one-off games though, we reckon players should be open to experiment in this manner. If your opponent vetoes the use of optional rules on the basis that they may interfere with his finely-honed battle plan, feel free to point and laugh at him for his lack of gaming spirit!

Next: Enslavers