| Zin is a god of discipline. Followers must remain pure of body and soul, refraining from dark magic and chaotic acts, and never consuming the flesh of intelligent beings. They must also tithe a fraction of all gold gained, preferably followed by donations of more. In exchange, worshippers may invoke Zin's wrath upon sinners, and eventually gain various divine protections. Zin's followers can convert to Elyvilon or the Shining One while keeping some piety.
Zin grants followers the ability to preach to the unenlightened masses, and powers to vitalise their bodies and gain divine stamina, protecting them from various afflictions as well as giving sustenance to the hungry. Later, followers gain the ability to imprison their foes temporarily. Followers can eventually find temporary safety in a divine refuge. As piety grows, followers will be protected from mutation, and Zin may even occasionally directly intervene to save a follower's life.
Zin likes it when you donate money (by praying at an altar) and you or your allies kill unclean or chaotic beings.
Zin dislikes it when you drink blood, you attack neutral beings, you deliberately mutate yourself or you or your allies attack monsters in a sanctuary. Zin strongly dislikes it when you perform cannibalism, you desecrate holy remains, you use necromancy, you use unholy magic or items, you attack non-hostile holy beings, you or your allies kill non-hostile holy beings, you attack allies, you transform yourself, you polymorph monsters, you use unclean or chaotic magic or items or you eat the flesh of sentient beings.
- Zin takes a 10% tithe every time you pick up gold, unless you're already at max piety. This tithe counts remainders (e.g., if you pick up two piles of 15 gold one after the other, Zin will take 1 gold piece from the first and 2 from the second). However, Zin knows if you try to save gold piles before converting to him ("Zin is a bit unhappy you did not bring this gold earlier."), and the tithe has a reduced effect in the Orcish Mines and on gold acquired. Paying a tithe has a chance to increase piety based on its size.
- Similarly, praying at Zin's altar will donate half your gold, granting a chunk of piety which will be distributed as you gain experience. You'll also receive an indication of what Zin's opinion towards you will be once the piety is fully distributed.
- Upon conversion, Zin takes some gold, but this provides more piety than a regular donation.
- Killing the spawn of chaos has a chance to grant piety. See the list of chaotic monsters and abilities for more details.
Zin dislikes it (i.e. piety loss) when:
- You drink blood from a potion of blood or a potion of coagulated blood.
- You attack neutral monsters.
- You allow sentient allies to die.
- You deliberately mutate yourself. This includes deliberately making yourself glow and drinking potions of beneficial mutation.
- You or your allies attack monsters in a sanctuary.
Zin strongly dislikes it (i.e. penance) when:
- You perform cannibalism.
- You desecrate holy remains.
- You use Necromancy. Casting Necromutation instead causes excommunication.
- You use unholy magic or items.
- You attack non-hostile holy beings.
- You or your allies kill non-hostile holy beings.
- You attack allies.
- You polymorph monsters.
- You use unclean or chaotic magic or items.
- You eat the flesh of sentient beings.
Zin will forgive accidental transgressions, i.e. performing a forbidden action via an unidentified item.
On average, your piety will decay naturally by 1 every 340 turns.
Piety level -: "Anchorite"
- Zin may protect you from a fatal instance of damage. The chance increases with Piety. Passive. No piety cost.
- Zin may protect you from the effects of Hell's mystical force. The chance also increases with Piety. Passive. No piety cost.
- Zin may protect you from mutation at a (Piety/2)% chance. Passive. No piety cost.
Piety level *: "Apologist"
- Recite - Preaches a verse from one of the four books of the Axioms of Law:
- Abominations, which harshly deals with chaotic monsters: Chance to cause bleeding, to smite, to illuminate, to sear their flesh, or to turn them into pillars of salt.
- Ablutions, which punishes unclean monsters and walking corpses: Chance to cause bleeding, to smite, to cause rot, to illuminate, to cast holy word, or to turn them into pillars of salt.
- Apostates, which applies to unbelievers and heretics (i.e. monsters who worship a god other than Zin, such as orcs of Beogh): Chance to put to sleep, to daze, to confuse, to fear, and to paralyze unbelievers, while heretics may suffer bleeding, smiting, blindness, muteness, illumination, paralysis, madness, and dumbness.
- Anathema, which combats demons and undead: chance to daze, to confuse, to fear, to illuminate, to cast holy word, or to turn them into pillars of salt.
If multiple books could apply, you are allowed to choose which to read from (e.g. whether to use Ablutions or Anathema on a skeleton). Recite takes three turns, during which you can move, fight, and evoke; anything that interrupts your speaking (potions, scrolls, spells, shouting, using other Zin abilities, or using a breath weapon) will cancel the Recite status. The effect of Recite is more powerful with higher piety and Invocations; stronger effects only occur at high power, but there's always a chance of weaker effects (or even no effect at all). Costs Breath.
Piety level **: "Pious"
- Vitalisation - Temporarily gives you the Vit status, which, while active, protects you from sickness, poisoning, confusion, petrification, rot, and stat drain, and boosts all your stats by Invocations/3. Also protects against the status effects caused by curare and the stings of red wasps and yellow wasps, while active. Gives a small amount of nutrition, but won't go past Full. Costs 1-2 Piety.
Piety level ***: "Devout"
- Imprison - Temporarily creates a silver-walled prison around an enemy, pushing away monsters adjacent to the target (if applicable). Duration depends on Invocations skill. Strong monsters may break themselves out before the effect ends on its own (chance of doing so depends on monster's HD). Costs 5 MP, 125-250 Food, and 4-6 Piety.
Piety level ****: "Orthodox"
- No new abilities.
Piety level *****: "Immaculate"
- Sanctuary - Creates a stationary Sanctuary with a radius and duration dependent on your Invocations skill, centered on yourself. Its radius will decrease as its duration runs out. So long as you remain within the radius of Sanctuary, no enemies can attack you (this protection extends to your allies, as well). If you or one of your allies attacks, Sanctuary is instantly dispelled and Zin considers it an evil act. Costs 7 MP, 150-300 Food, and 15-23 Piety.
In addition to preventing enemy attacks, you enjoy the following effects from Sanctuary:
- Traps are revealed.
- Clouds dissipate.
- Your allies are recalled and protected against Abjuration.
- Monsters may be scared away.
- Undead and demons are subject to Holy Word, which slows, damages, and scares them.
- Magical contamination discharges are greatly reduced.
- Hell's mystical force will not strike you; any previous effects will linger, however.
- Blood is cleaned from tiles.
Piety level ******: "Bringer of Law"
- Cure All Mutations - Immediately removes all mutations from your character, both good and bad. Can only be used once per game. No piety cost.
- 20% chance: If possible, remove 1-7 random good mutations. Otherwise, reroll from the remaining options.
- 30% chance: Summons either (1d3 + XL/10) hostile angels (more likely if you are high level) or a swarm of "creeping doom" (i.e. random insects, arachnids, and worms).
- 20% chance: Recites the Axioms of Law at you, inflicting confusion, sleep or paralysis (equal chance of each).
- 20% chance: Halves your current nutrition level.
- 10% chance: Makes an extremely loud noise at your current position.
Zin works through somewhat more subtle means than most other gods. Rather than directly killing, Zin empowers you to disable monsters with Imprison and various status effects (via Recite) while protecting you from various kinds of harm.
In terms of overall god strategy, remember that you can switch amongst Zin, Elyvilon, and the Shining One without incurring wrath, and you even get some starting piety with your new god choice. All three of these gods use Invocations skill. Also, so long as you do not worship an evil or chaotic god at any point later on in the game, you will not incur wrath if you leave any of these three gods.
In spite of the fact that Zin abhors chaos, Recite produces a variety of random effects. Recite's list of effects grows along with your Invocations skill and your piety, but weak effects are always possible. Monsters resist it based on their hit dice, not their magic resistance. Do note that reading scrolls, using other Zin abilities, casting spells, drinking potions, using a breath weapon, and shouting or commanding allies via the (t)ell command will interrupt recite.
Vitalisation boosts all your stats for a low piety cost, and while active makes you immune to sickness, poisoning, confusion, petrification, rot, and stat drain, but it won't cure these ailments if you already have them, so activate it preemptively upon encountering an enemy that can inflict such effects on you. (Something of a niche case, but Vitalisation does prevent the status effects that curare, yellow wasps and red wasps cause via their poison.) Also note that Vitalisation prevents the poisoning status but does not actually provide rPois, and thus does not lower the damage from the impact of spells like Poison Arrow or Venom Bolt.
Sanctuary is one of the most powerful emergency abilities in the game. Use it when you're surrounded and the situation is quickly going pear-shaped, though make sure you have an escape route too, lest Sanctuary only delay rather than prevent your death. Note that you can't recast Sanctuary while you already have one still active, and that it costs a hefty 15 piety to invoke.
In 0.14 Vitalisation will grant poison resistance, and Zin won't mind when you allow your sentient allies to die.