Sleeper Island Summoning Guide

Sleeper Island uses custom rules for summoning spells, to make combat easier and provide a better experience for all players involved. 

Change 1: Minion Limit

Characters are limited to 4 minions or 4+1 if you have a familiar and/or animal companion.

Change 2: Upcasting

Upcasting spells no longer increases the number of creatures summoned.
Instead the CR maximum for the respective summons are increased by 1 per duplicate set.

Example: If it would normally double then CR+1, if it would normally triple then CR+2, if it would normally quadruple then CR+3.

CRs are rounded down to nearest whole number if the resulting CR is over 1. Single summoned creatures instead increase their CR by 1 per spell level upcasted, this is in addition to any behavior that currently exists with increasing CR when upcasting.

Change 3: Encountering creatures

The player gets the choice of what creatures are summoned. The player must have encountered the creature type before and succeeded in an arcana/religion/nature check (whichever is appropriate). The DC is equal to 10 + the creature’s CR, rounded down.

If the player does not specify a creature type, it is up to DM discretion as to what creature is summoned, if any.

Only official or third party unofficial stat block creatures can be summoned – homebrewed DM creations are exempt from your summoning attempts.

Change 4: Non-concentration Swarm Tokens 

Each swarm token can only have one creature type attached to it (e.g. zombie or skeleton but not both).
Each swarm token takes a single minion slot.

They are named “Swarm of {creature type} {number of creatures in swarm}”

Any aoe damage is multiplied by the number of creatures in the swarm.
The swarm’s number should be updated AFTER combat.

You are responsible for keeping track of this and if found to not be obeying the rules will have your summoning privileges revoked and possibly be kicked from the campaign.

They either do:

  • 1 attack roll, full damage (add total damage of all mobs together)
  • No attack roll, compare to-hit with AC (total damage = average/mob # of mobs hit %)
    Hit % = number of average hits for the mobs.

Change 5: Maximum HP

Single summoned creatures receive a maximum of their allowed hit points, when first summoned.

Change 6: Casting Time

All summoned spells require either their current casting time or a full minute casting time, whichever is longer.

To compensate, the spells durations are doubled, if the caster desires

Summoning Spells Table

Spell NameCasting TimeDurationEffect
Phantom Steed1 minute1 hourMax HP Mount
Unseen Servant1 minute2 hoursDuration Increase
Conjure Animals1 minute2 hours (C)Max HP Animal Swarm, Duration Increase, Swarm Token
Conjure Celestial1 minute2 hours (C)Max HP Celestial, Duration Increase
Conjure Elemental1 minute2 hours (C)Max HP Elemental, Duration Increase
Conjure Fey1 minute2 hours (C)Max HP Fey, Duration Increase
Conjure Minor Elementals1 minute2 hours (C)Max HP Elemental, Duration Increase, Swarm Token
Conjure Woodland Beings1 minute2 hours (C)Max HP Being, Duration Increase, Swarm Token
Danse Macabre1 minute2 hours (C)Max HP Undead, Duration Increase, Swarm Token
Infernal Calling1 minute2 hours (C)Max HP Devil, Duration Increase
Summon Greater Demon1 minute2 hours (C)Max HP Demon, Duration Increase
Summon Lesser Demons1 minute2 hours (C)Max HP Demon, Duration Increase
Animate Objects1 minute30 minutes (C)Max HP Object, Tiny and Small size not allowed, Duration Increase, Swarm Token
Bigby’s Hand1 minute30 minutes (C)Duration Increase only
Giant Insect1 minute30 minutes (C)Max HP Insect, Duration Increase, swarm token
Tiny Servant1 minute8 hoursMax HP Servant
Animate Dead1 minuteInstantaneousMax HP Undead, Swarm Token
Bones of the Earth1 actionInstantaneousUnaffected, Not in rule scope
Create Homunculus1 hourInstantaneousMax HP Homunculus
Create Undead1 minuteInstantaneousMax HP Undead, Swarm Token
Find Familiar1 hourInstantaneousUnaffected
Find Greater Steed10 minutesInstantaneousUnaffected
Find Steed10 minutesInstantaneousUnaffected
Finger of Death1 actionInstantaneousMax HP Zombie
Mighty Fortress1 minuteInstantaneousUnaffected
Negative Energy Flood1 actionInstantaneousMax HP Undead
Planar Ally10 minutesInstantaneousMax HP Ally
Simulacrum12 hoursUntil dispelledUneffected

Summoning Items Table

Item NameCasting TimeDurationEffect
Bowl of Commanding Water Elemental1 Minute2 hours (C)Max HP Elemental, Duration Increase
Brazier of Commanding Fire Elemental1 Minute2 hours (C)Max HP Elemental, Duration Increase
Censer of Controlling Air Elemental1 Minute2 hours (C)Max HP Elemental, Duration Increase
Stone of Controlling Earth Elementals1 Minute2 hours (C)Max HP Elemental, Duration Increase
Elemental Gem, Emerald1 Action2 hours (C)Max HP Elemental, Duration Increase
Elemental Gem, Red Corundum1 Action2 hours (C)Max HP Elemental, Duration Increase
Elemental Gem, Blue Sapphire1 Action2 hours (C)Max HP Elemental, Duration Increase
Elemental Gem, Yellow Diamond1 Action2 hours (C)Max HP Elemental, Duration Increase
Bag of Tricks, Tan1 MinuteUntil DawnMax HP Creature, Duration Increase
Bag of Tricks, Gray1 MinuteUntil DawnMax HP Creature, Duration Increase
Bag of Tricks, Rust1 MinuteUntil DawnMax HP Creature, Duration Increase
Hat of Vermin1 Action1 hourMax HP Creature
Ring of Djinni Summoning1 Minute2 hours (C)Max HP Djinni, Duration Increase