Adjust BEAM_POISON and BEAM_POISON_ARROW player poisoning for new system

Again, there is no clear way to map old poison values directly onto
the new system, even if the intent were to preserve them as close as
possible (which I do not think is even intrinsically desirable), so
these are a first pass at new formulas.

The amount of lingering poison inflicted by poison beams is now based
on a randomized fraction of the pre-AC damage of the beam (meaning
greater naga venom bolt will leave more poison in your system than
deep elf mage venom bolt would). This is probably a buff to venom bolt,
but it was never the scariest spell in the first place, and damage
numbers on either side of the equation can be adjusted after testing.

1 files changed, 8 insertions, 4 deletions

diff --git a/crawl-ref/source/ouch.cc b/crawl-ref/source/ouch.cc
index cee772c5d8..6d9fd31274 100644
--- a/crawl-ref/source/ouch.cc
+++ b/crawl-ref/source/ouch.cc
@@ -200,7 +200,10 @@ int check_your_resists(int hurted, beam_type flavour, string source,
     case BEAM_POISON:
         if (doEffects)
         {
-            resist = poison_player(coinflip() ? 2 : 1, source, kaux) ? 0 : 1;
+            int pois = div_rand_round(beam->damage.num * beam->damage.size, 4);
+            pois = 3 + random_range(pois * 2 / 3, pois * 4 / 3);
+
+            resist = poison_player(pois, source, kaux) ? 0 : 1;
 
             hurted = resist_adjust_damage(&you, flavour, resist,
                                           hurted, true);
@@ -223,9 +226,10 @@ int check_your_resists(int hurted, beam_type flavour, string source,
 
         if (doEffects)
         {
-            int poison_amount = 2 + random2(3);
-            poison_amount += (resist ? 0 : 2);
-            poison_player(poison_amount, source, kaux, true);
+            int pois = div_rand_round(beam->damage.num * beam->damage.size, 3);
+            pois = 3 + random_range(pois * 2 / 3, pois * 4 / 3);
+
+            poison_player((resist ? pois / 2 : pois), source, kaux, true);
         }
 
         hurted = resist_adjust_damage(&you, flavour, resist, hurted);