I've spent the last few weeks writing and refining a fast play set of Anglo-Zulu War rules which will start a regime of play testing soon.
The next question is whether to write a completely separate Sudan ruleset or simply add a Sudan supplement.
On the surface the two conflicts seem very similar:
British regulars with modern breech-loading rifles.
Large numbers of tribal warriors.
Importance of volley fire.
Squares and defensive positions.
Small colonial columns operating far from support.
However, the Sudan also introduces Egyptian troops, camelry, more cavalry and generally more firearms on the native side.
My feeling is that perhaps 80-90% of the mechanics could remain unchanged, with differences handled by troop types and a short supplement. This, of course, begs the question as to the worth of my AZW rules!
What do those who game both periods think? Would you use one core ruleset for both wars, or are the differences great enough to justify separate rules?