Magic cancellation (GnollHack)
Magic cancellation (or "MC") in GnollHack is for resisting a wide variety of magical or unusual melee attacks. It is significantly changed from how it works in vanilla NetHack, now stacking and operating on a different scale.
Protection Changes from NetHack
In addition to what MC blocks in vanilla NetHack, MC in GnollHack also blocks:
- charm from nymphs
- disease, including mummy rot from mummies
- gold-stealing from leprechauns
- leg damage from xans
- petrification
- seduction
- stunning
- strength, dexterity, or constitution-stealing effects
However, these effects still need to come from the appropriate attack types. For example, the petrifying touch attack of a cockatrice might get blocked, but the petrifying gaze of Medusa will not.
The following are blocked by MC in vanilla NetHack, but are not blocked by MC in GnollHack:
Scaling and Stacking
MC in GnollHack stacks up to 25. However, each individual point has less impact than levels of MC in vanilla NetHack.
The following are the odds of an effect MC can block actually being blocked by MC:
| GnollHack MC | Effect probability | Notes |
|---|---|---|
| 0 | 100% | |
| 1 | 90% | |
| 2 | 80% | |
| 3 | 70% | MC1 in vanilla |
| 4 | 60% | |
| 5 | 50% | |
| 6 | 45% | |
| 7 | 40% | MC2 in vanilla |
| 8 | 35% | |
| 9 | 30% | |
| 10 | 25% | |
| 11 | 20% | |
| 12 | 18% | |
| 13 | 16% | |
| 14 | 14% | |
| 15 | 12% | |
| 16 | 10% | MC3 in vanilla |
| 17 | 9% | |
| 18 | 8% | |
| 19 | 7% | |
| 20 | 6% | |
| 21 | 5% | |
| 22 | 4% | |
| 23 | 3% | |
| 24 | 2% | |
| 25 | 1% |
Despite the diminishing returns, extra points of MC are still valuable against certain attackers, whose cancelable attacks treat the target's MC as lower than it really is. For example, the wood nymph ignores 5 points of MC.
Additional Sources of MC
To account for the change in MC, many pieces of non-magical armor have their MC levels greatly increased, and the ring of protection now also provides MC equal to its enchantment level.
Every three points of protection you have increases your MC by 1. Likewise, armor enchantments increase MC by 1/3 per-level, individually rounded down. (Wearing three +2 armors will not provide extra MC, but a +6 armor will provide an extra MC2.)
GnollHack monks get additional MC as they level up, along with additional AC. This MC only applies while they're not wielding a weapon, wearing body armor, or using a shield.
Last-but-not-least, weapons "of defense" provide MC equal to their enchantment level, along with a matching boost to AC.