Bind Demon

Force an injured demon to do your bidding.

Bind Demon is the Warlock's capture skill (Demon Skills, level 30, requires Engorge and Summon Defiler, the end of the tree). It is a channel (srvmissilea binddemonchannelmaker) that tries to bind a demon at low life; a bound demon is a pet of its own type (pettype binddemon, petmax 1), so it does not count against the summon cap, and it is buffed by this row and by Demonic Mastery and Blood Oath. Two numbers decide it: the chance to bind, 55% at level 20, and the four affixes the captive gains at levels 5, 10, 15 and 20.

The numbers

• Mana is a channel cost: startmana 9 to begin, then the tooltip's mps line, 0.78 a second at level 1 and 1.08 at level 20 (mana 50, lvlmana 1, manashift 2).
• Chance to succeed is dm34, a diminishing curve from Param3 (12) toward Param4 (64): 19% at level 1, 47% at level 10, 55% at level 20, plus Param8 (100) ÷ 100 = +1% per Death Mark hard point. Param3 and Param4 are, by the table's comments, the growth rate and cap for the capture that monpet.txt references.
• Damage (item_normaldamage, flat) is ln43: Param4 (64) plus Param3 (12) a level, +292 at level 20. The Param13 (50) and Param14 (25) the comments call "flat damage bonus baseline / per level" are not what the calc reads.
• Damage percent (damagepercent) is ln56 plus Demonic Mastery's Damage line: Param5 (75) plus Param6 (5) a level, +170% at level 20 before the mastery. The tooltip prints it from the passive stat, which cannot be embedded.
• Life is calc1, which is 0: the row's "HP % Modifier" adds nothing, and Param9 (100) and Param10 (5), the comments' "health percent increase", are not read by any calc on the row.
• Attack rating (tohit) is ln78 plus Demonic Mastery's Attack Rating line; Param7 is empty and Param8 is 100. Defense is ln91 on Param9 (100). Attack speed is Demonic Mastery's attack speed line capped at 25%; Run/Walk is Demonic Mastery's dm91.
• Affixes read lvl: calc2 gives monster affix 5, Extra Strong, from level 5; calc3 affix 6, Extra Fast, from level 10; calc4 affix 27, Spectral Hit, from level 15; calc5 affix 30, Aura Enchanted, from level 20. The tooltip's four lines (lvl/5, lvl/10, lvl/15, lvl/20) only flag whether each is on.

The chance, damage and affix lines read lvl, so +skills from items count; the Death Mark term reads blvl.

How it works

The bound demon is a captured monster, not a summon from a row: calc7 (2) sets its life regeneration behaviour to "hp regen for all". It gets Blood Oath's resist all (passive_summon_resist = skill('Blood Oath'.dm78)) and physical damage reduction (dm91), copies your item_pierce_damage_immunity stat (see Monster Physical Immunity is Sundered), and the row is stsuccessonly 1, so the bind state is applied only when the roll succeeds. Param11 (15) and Param12 (10), "Life % / dmg % syn other demon skills", are on the row but no calc in these facts reads them.

The chance is a roll per attempt and it is diminishing: 47% at level 10 and 55% at level 20, so ten more levels buy 8 points, and twenty Death Mark hard points buy 20.

Synergies and +skills

One synergy line in the tooltip: Death Mark, +1% chance to bind per level (Param8 ÷ 100), from hard points. The row also reads Demonic Mastery's damage, attack speed, attack rating and run/walk lines and Blood Oath's resist all and physical damage reduction. Bind Demon gives a synergy to no other skill.

Against players

Bind Demon targets monsters; it never touches a player. A bound demon's hits on a player are cut to 17% of their value by the player-versus-player rule (difficultylevels.txt PlayerDamagePercentVSPlayer), see Player versus Player.

Build notes

• Level 20 is where the last affix (Aura Enchanted) arrives, and +skills count toward it, so hard points plus items reaching 20 is the target.
• Death Mark hard points are the cheapest chance: +1% each against the diminishing curve's +8 for levels 10 to 20.
• The bound demon's life line on this row is 0; its toughness is Blood Oath's resist all and the captured monster's own life.