Comments welcome.
Summoning is a “push your luck” custom class ability. It costs 2 customs for a summoner level equal to 1/2 class level or class level-5; or 4 customs for a summoner level equal to class level. At the Judge’s option, there may be variants that can only summon certain kinds of creatures (an “undead summoner,” for example, or an “normal animals summoner”) which costs half as many customs.
A summoner has a repertoire of one species per summoner level (a summoner-4 means four species). Swapping out species is identical to swapping out spells for a mage (same time, cost, etc.). Maximum HD is twice the summoner level.
To summon a creature, roll 1d6 + summoner level. If the result is equal to or above the creature’s Summon number, one creature is summoned. If the result is lower, the summoner fails and cannot attempt further summons for one hour. Summoning is treated as casting an arcane spell for all purposes (declare at beginning of round, interruption, etc.).
The Summon number is equal to 3 + HD + (1 per special • abilities). Round 0.5 up. A HD of [1 hp] is ignored, [1d4] is treated as 0.5, and all penalties/bonuses ([6+1]) are ignored. An ordinary bat ([1 hp]) has a Summon 3; a giant killer bee ([1d4•]) has a Summon 4; a black pudding ([10•]) has a Summon 14; an efreeti ([10•••]) has a Summon 16.
Summoning more creatures at once is possible. Increase the Summon number as follows:
+2: 1d4 creatures
+3: 1d6 creatures
+4: 1d8 creatures
+5: 2d6 creatures
+6: 3d6 creatures
+7: 4d6 creatures
+8: 6d6 creatures
+9: 8d6 creatures
+10: 10d6 creatures
Once summoned, a creature is bound to obey you until one of the following conditions is met:
(a) One turn per summoner level has passed.
(b) The creature has fought for you in one encounter.
(c) The creature has performed one significant task (anything that takes one turn or more; granting a wish; doing something radically against its nature).
When the binding wears off, the creature is free. To unsummon the creature, make a second Summon roll. A successful summons banishes the creature; on failure, the summoner may not attempt any further banishments for one hour. Killing the creature or convincing it to leave automatically banishes it. A summoner who summons multiple creatures and then sends them into combat can attempt to banish all of them at the end of the combat; use the highest Summon number, and add +2 to the Summon per doubling of creatures.
Summoners can banish conjured creatures in the same fashion.
Most creatures resent their servitude!