A second in a series of posts about multiclassing options in 13th age. Cleric/Necromancer has a narrower range of talent builds available than Commander/Paladin, as neither class gets bonus talents. Spell preferences are much easier to adjust on the fly than talent builds.
A note before proceeding: the Key Stat for Necromancer/Cleric is listed differently in the two different entries in the Key Stat chart on p 107, either Int/Wis for Cleric/Necromancer or Int/Cha for Necromancer/Cleric. Common sense and looking at the spellcasting stat of the cleric class tells us it should be Int/Wis. It is this assumption I am proceeding under in this guide.
The Cleric is a great class for multiclassing. It provides access to light and heavy armor, solid talents, and a huge variety of quick action spells that support your party. It is a little bit soft offensively without considering its buffs to be part of its DPS, though, and I've seen a (small but notable) number of posts arguing both that you don't need a dedicated healer in 13th Age and that the cleric gives up too much of the stuff you do need in exchange for "overhealing." As weird as it may sound to many players, some of us like being healers - perhaps the little brothers of DMs, invited along only on condition of playing cleric, have just been conditioned this way. I dunno. I can see how the 13th Age cleric would be spiced up by adding something else, though, and my vote is Necromancer, for the following reasons.
First, Necromancer offers even more healing to the Cleric's already powerful healing mastery. Channel Life + adventure feat gives a Necromancer/Cleric 4 heals per battle, which is huge. Death's Call offers a quick action healing for correctly identifying the next creature to fall, again, per battle (for bonus points, at high levels you can nominate a low HP ally before whacking him with Cone of Corruption accidental-like, then heal him back up with the recovery generated by Death's Call, a move called "Death's Wrong Number"). Now, both of those MIGHT have a downside, but what's life without a little risk? Maybe it'll all turn out okay!
Second, there are 3 Necromancer spells (Channel Life, Circle of Death, Cone of Corruption) that potentially damage your allies. They get compensated for this by being quite good at their job (Circle of Death, for example, is typically stronger and hits more targets than Fireball at the cost of lightly hitting allies and triggering late in the fight), but your clerical (and possibly necromantic) healing magic can heal allies of both enemy damage AND your own friendly fire, at once limiting your "overhealing" and unlocking really potent offensive options while limiting their downsides.
Third, a lot of the Cleric's offensive power is tied up in buffing allies attacks, while its core competency is in improving defenses and healing incoming damage. A lot of the Necromancer's power is tied up in creating more allies, which both creates more attackers and more meat shields. These interact synergistically to create new and interesting options that are both effective and highly pleasing to "pet class" enthusiasts. In some ways, Cleric/Necromancer creates a strong parallel to the Druid's Animal Companion talent, in that the combination brings both pets and the means to buff them.
Fourth, even outside of summons Necromancer is significantly blastier than the Cleric, and given that the Cleric's buffs and heals are often quick actions you can typically combine a Necromantic offense with Clerical defense simultaneously.
Fifth, the cleric is one of the few classes that can get by without ever rolling an attack from its class, and in conjunction with Wasting Away this opens up some interesting stat choices - see section III, below.
Sixth and finally, it's tradition! Tradition! Those who cut their teeth on 2nd or 3rd ed D&D are familiar with clerics, not wizards, having the strongest necromantic abilities. But in 13th Age clerics are the heal/buff/melee variety, with nary a 3rd level Animate Dead spell to be found. Fixed!
II. RACIAL CHOICES:
With intelligence or wisdom on offer, you've got human, dwarf, high elf, wood elf, gnome, aasimar, or tiefling as stat-compatible choices.
Human's bonus feat is always welcome, and their improved initiative does heavier duty than usual for necromancers as summons and skeletal minions both go on their master's initiative (especially nice for Blackamber Skeletal Warriors, but that's a late game benefit). Your ability to increase the escalation die can unlock or upgrade some of your spells (Circle of Death, the Last of the Wine, epic Chant of Endings), and your minions when feated (or, in case of summons, assisted via quick action) can add the escalation die to their own rolls. All in all, a great choice, and probably the best generalist choice.
Players looking to compensate for necromantic fragility can consider dwarf for the additional self-heal, but given your lower recovery values from Wasting Away a defensively minded-player might instead grab aasimar for a +2 boost to all defenses until hit. If you use the champion feat for Halo you can use your own heals to both undo incoming damage and restore your defenses, a nice double-dip. Or you can go with high elf for the "distance and intervening meat shields are the only armor I require" argument. Any of these are viable ways to shore up your defenses.
Wood elf has the potential to really unleash a storm of spells, whether the devastation of Circle of Death-> Judgment or a double Channel Life and a Heal all in the same round. Its huge potential benefit is balanced by its unpredictability, and on a poor initiative roll a single Elven Grace success may be roughly equivalent to Quick to Fight, so it's not a no-brainer, but highly worth considering.
Tiefling or gnome don't, in my opinion, offer quite a much as any of the above.
III. STAT CHOICES
The interaction between Wasting Away's low Con requirement, its adventurer feat attack bonus for necromancer spells, and the large number of non-attack cleric spells leaves you a bit more choice for stat builds than is normally available for multiclass characters. The question is, do you want the flexibility to draw on attacks from both classes, or are you willing to only attack as a Necromancer and simply use heals & buffs from Cleric?
It's not a simple choice. Both the Necro attack at-wills have some drawback (no control of target for Chant of Endings, slowness of ongoing damage and potential disruption by opponent using a standard action to break a stack for Death's Gauntlet). One option, then, is to take both a Death's Gauntlet AND Javelin of Faith, giving you a speciality option and a solid-but-vanilla option. Another is simply to take Javelin and save your Necro slots for your amazing dailies. In either case you can shuffle in quality Cleric attacks like Spirits of the Righteous or Sphere of Radiance. Flexibility is worth a lot. This build also allows you to wear heavy armor and either only take non-attack Necromancer spells (summons, forms, Wave of Decay, Death's Call, Feigned Defeat) or switch into heavy armor after you've expended all your Necromancer spells in a day. I wouldn't build a whole character around this concept, but it gives variety and options.
Giving up the above flexibility lets you really spread out your stats. If you select only Cleric spells without an attack roll and run Chant of Endings, this will allow you to run starting post-racial 16/16 or 17/17 Int/Wis with 8 Con. Using the Wasting Away adventure feat, your attack bonus will meet (at 16/16) or exceed (17/17, at levels 4,5,6 and 10) characters with 18/18 in their key stats. This gives you the option for investing in Dex for great initiative and AC (good synergy with Holy One) and/or higher Charisma to open up talent benefits (notably, with Redeemer)