Wikinger is a realism mod that has quickly become my favorite way to play CoH2. If you've never played realism mod like Spearhead or Wikinger than essentially realism makes combat a lot bloodier. Units shoot at each other from farther ranges, infantry will die much faster, and vehicle/tanks are much more vulnerable to AT fire. It can definitely be strange going from regular CoH2 to Wikinger but there is a lot of very interesting things worth playing the mod for.

By far one of my favorite things is the tech trees. Each nation have 4 doctrines that have a tech tree that unlocks units, abilities, and call ins that shape the unique way a doctrine plays. The really interesting part is that you have to actively spend your CP points unlocking the various things within the doctrine. This offers a lot of interesting decisions throughout the game. Should you spend you CP to get upgrades for your infantry now? Maybe save your CP to unlock a powerful tank? Or maybe get some artillery support ready for use? It can have a lot of depth and really change how a single doctrine can be played.

Really the main issue is that understanding what the doctrines is one of the hardest parts of learning Wikinger. The mod gives limited explanation as to what a specific ability or unlock does. So this is where this guide comes in. It will go through each and every doctrine within Wikinger and give detailed explanations of what each unlock does for you. Hopefully this will make playing Wikinger a much easier experience.

If you are completely new to Wikinger I highly recommend giving this Wikinger Basics guide at least a glance as it explains many of the new/complicated aspects of Wikinger.
https://docs.google.com/document/d/e/2PACX-1vQVfbgVeh16dBRA-lhSuFhTDDtbNkkPs-8dbeRxu6tdI-SqO2r7nGAA9LnUGl2GFDo6yJLThL9MC5qN/pub

General Soviet Unit Guide
The following guide mainly covers the various units that exist in various doctrines.
https://docs.google.com/document/d/e/2PACX-1vSHBRbpImonIyl3p37nW2hJfpTqEhyPxR11L-NoYBKhY7-3ehnsKvgEvtg617f6SdXkTq7gSwrDvowq/pub

Guards Tank Doctrine

https://docs.google.com/document/d/e/2PACX-1vSFvMcClGagtoDYvYRAWlyU29nfklfHOAhIDdJab8Kvjz-lE-la9g5ox8U43hP3roAUcRooS4GC_EeV/pub
Complexity: Easy
Pros: Cheap spammable T34s + Strong Late game armor with IS2 and T-34-85s
Cons: Lacks in direct fire + Infantry mostly mediocre

Guard Rifle Doctrine

https://docs.google.com/document/d/e/2PACX-1vQvwHN14UNmevVM4BvNhrobtVrskWKs7R9_WSKaDj5pYyFdNAjVZAu9wtFhQSiwnD_tQ3Cc1DzE2uXi/pub
Complexity: Medium
Pros: Powerful elite infantry + Some of the best Soviet AT Infantry
Cons: Losses can be hard to replace + Lacks heavy armor beyond IS1

Breakthrough Artillery Doctrine

https://docs.google.com/document/d/e/2PACX-1vSmfCwCMiun_qHelTp1hbKl4bBW4jPoE6lSVDhCg2393lII2-MjRpNeoMsz3MUwWSD2KV3ywDVT7tX1/pub
Complexity: Hard
Pros: Numerous buildable artillery pieces + Options to handle almost anything it can face
Cons: Infantry mostly lacks LMGs or SMGs + Late game is reliant on specific expensive units

OMBSOM Doctrine

https://docs.google.com/document/d/e/2PACX-1vQ6Pk6b5-mYXrq8U33ZlhCJXjzht49W9bAnF5YWKJNHzhToFRNoXC9GQ0bxzvRRgELFi328fDkOcLuJ/pub
Complexity: Hard
Pros: Tons of camouflage for ambushes + Late game can spam Rocket artillery and T-34-85s
Cons: Weak without vet + Early game is quite rough + Recon can negate camouflage

General USA Unit Guide
The following guide mainly covers the various units that exist in various doctrines.
https://docs.google.com/document/d/e/2PACX-1vSRfwCnlhAFa3UiB2NqtIKxoxqnwPL-WUPu-OM_biQmPwo_phA__J1Qmmj9Zy4-ydnUluNkVDrpzees/pub

US Infantry Doctrine

https://docs.google.com/document/d/e/2PACX-1vRMMiWq9UNITK1V-Su_ExKngFXIZIXkKqv7BfRpIwQK2KkpKapv1Vo2cWEalple8yLm1_K4VhM2ySbP/pub
Complexity: Easy
Pros: Highly Adaptable + Well Scaling Infantry
Cons: Lacks offensive heavy tanks + Infantry very expensive to reinforce and upkeep

US Armor Doctrine

https://docs.google.com/document/d/e/2PACX-1vQdxjiFqGXkGUD4eKiXoV3Y27EbiOgKq5VYWT5ZYC7qFrFjKfrn52eVInb_wyqVCmluYFN6dJa8OJEQ/pub
Complexity: Medium
Pros: Cost Effective Sherman Spam + Access to Heavy Armor like Pershing
Cons: Limited infantry options early on + Lacks strong indirect fire

US Artillery Doctrine

https://docs.google.com/document/d/e/2PACX-1vRzktCcCn-vJ_CqQRqJ_XjDObICQPbBKeE6R9B635JI7USyyCzyiNTBN-L44lA3ljwcf1sn4ba2hw68/pub
Complexity: Hard
Pros: Plentiful indirect and off map options, Numerous defensive tools such as cheap mines and fake tanks
Cons: Requires careful spending to build indirect while also holding frontline, Munition Intensive

US Airborne Doctrine

https://docs.google.com/document/d/e/2PACX-1vRTwvkVT729MoINg3dQPVRZkptcuVdl8Y03RUTnoN7rhoxgoPfqg7SbiEDsFIMqu9CGigRWU97Oj0X4/pub
Complexity: Hard
Pros: Numerous ways to quickly bolster frontline forces + Plentiful and powerful air strikes
Cons: Can run out of munitions limiting airstrike potential, Manpower heavy due to reliance on call ins late game.

General UKF Unit Guide
The following guide mainly covers the various units that exist in various doctrines.
https://docs.google.com/document/d/e/2PACX-1vS2n_qG5JtPR0iRsr6bzutc87k16d0gAwcmI7W_fkBloyuwHiLa4fQG2ZmoxIZ8tN_3IWfEDrP3tWWq/pub

Guards Armored Doctrine

https://docs.google.com/document/d/e/2PACX-1vSprpsFnRCuT6X6H8A1loovVl39TYl9gR-X9Z31_GHmxqNjaONvAXaOKqo7PeNGd_WppUsy7LREJ0Bh/pub
Complexity: Medium
Pros: Long Range Tank Destroyer Fireflies + Cromwell Spam
Cons: Infantry is underwhelming + Reliant on Fireflies to keep up with axis armor

Royal Canadian Artillery Doctrine

https://docs.google.com/document/d/e/2PACX-1vTYjDEd8gWVaJQ2pM3qQBoqj_TU1YpFLGOc5bLgz1I5FdzV_MyGVyhpBGSMyCHeGoZO8AuQUfDE4FmT/pub
Complexity: Easy
Pros: Potent Artillery options for constant barraging + Strong Infantry
Cons: Relies heavily on M10s and Fireflies to contain enemy armor which can be overwhelmed

Commandos Doctrine

https://docs.google.com/document/d/e/2PACX-1vQlztKPyvytq8VUc_i0RP9r0IzVb966OknCw-1UoVTKKx82MnQukZnJWEMcY7HkBIeBVVzuuifHESA9/pub
Complexity: Medium
Pros: Potent elite infantry across the board + Strong anti infantry tanks
Cons: Lacks tanks that can directly kill other heavy tanks + Munitions stretched thin between abilities and expensive airstrikes

52nd Lowland Infantry Division Doctrine

https://docs.google.com/document/d/e/2PACX-1vTDUYkECQC30607b58Znex0xAQhMw-XuA-Nbc2l1lwy5hWGN4uQsD_B_39py0HafQ-uQ9SmiBZnW8dc/pub
Complexity: Easy
Pros: Well rouinded infantry + Numerous potent call ins + Solid tools for most other needs
Cons: Lacks solutions to superheavies + Armor is tough but struggles to kill other tanks until late game

General Wehrmacht Unit Guide
The following guide mainly covers the various units that exist in various doctrines.
https://docs.google.com/document/d/e/2PACX-1vSzO3zRobNSs1VcW9aCAtu8gltLnsTNbE4AEciubryRyiKP_GpA3AvfCXqvMShf_YgVekdeqWLpVVXB/pub

Panzerjager Doctrine

https://docs.google.com/document/d/e/2PACX-1vSWcHZ3l1Ytlm75i0JhSYd6SaOzD-j1Oiyt-PZvcsX7OsB0Ycf3XBsOfZHvXasGZf8bkU8YCCCWxSO6/pub
Complexity: Medium
Pros: Wide variety of Tank Destroyers + Cheap and spammable infantry with volksstrum + Jagdtiger Ace
Cons: No off map support + Armor lacks Anti Infantry options

Panzergrenadier Doctrine

https://docs.google.com/document/d/e/2PACX-1vTijxzPCUiMZ316BzqXPr0OyBb0rWOnZsXrypWT0MYpMaEVVJFi_WjTL2AgIDHYNJEZaNZ4hrAthKcw/pub
Complexity: Easy
Pros: Cheap and upgraded Panzer IVs + Well Rounded Infantry + Strong Call ins
Cons: Limited off map support + Lacks any super heavy tank unlike most German doctrines

Volksgrenadier Doctrine

https://docs.google.com/document/d/e/2PACX-1vT_8RXx4Xs2jJfvK0JbobtcW8wGfKe1xBwxHf8Nd-ip92antLZg_Cp475_ROwZoL--vfXAsm4xkyHaK/pub
Complexity: Medium
Pros: Cheap units and free upgrades lead to a very easy to manage economy + Powerful infantry + Strong Late game armor with Panther Ace and Strumtiger
Cons: Mostly castmate tanks destroyers until late game + Many important upgrades are spread in various CP trees + Reliant on Panther Ace/Strumtiger for heavy killing power

Static Infantry Doctrine

https://docs.google.com/document/d/e/2PACX-1vR0FyZJ-IAaw3bmlwKqFOZsZweFusY-UAHZUqQYdCSGZqJOyzpC91Jayiemwxby9gcMg_H3TI4sQ3vF/pub
A second link with the buildables
https://docs.google.com/document/d/e/2PACX-1vRfulTPoUmX9EKT86HE5-Zv3Vb_iQW9rE8MsQ1yB6wXCPNskBk8P_B6yuzgshk4Hz02wgTqNWggldSb/pub
Complexity: Hard
Pros: Numerous artillery options + Large amount of MGs + Buildables are incredibly potent at defending
Cons: Buildables are expensive + Lacks offensive power

General SS Unit Guide
The following guide mainly covers the various units that exist in various doctrines.
https://docs.google.com/document/d/e/2PACX-1vQ9Iyl_VgXVf2F0c47l8NBJsfKibOFYXoFBq6eXPguKRjMxBDUS7GceRAwJKD-mQoTtvlE3rTi4rpyl/pub

Wunderwaffe Doctrine

https://docs.google.com/document/d/e/2PACX-1vSDn6pv6c1IcwdWWd5a6L9yi64MVzN5qEZ8b18sLV9Oi4TKlWFWkJxUkF0ALnptv5VN6kxXfNTAH5hK/pub
Complexity: Expert
Pros: Some of the best late game with buildable Tigers (both 1s and 2s) + Incredible scaling on many units + Can get a very fast Tiger Ace
Cons: Tech is incredibly expensive + Weak starting infantry + Many moments of weakness before late game

SS Artillery Doctrine

https://docs.google.com/document/d/e/2PACX-1vRhUBLAo0_oYbEpy7Xc53WmXo1vElQMuJzrx_Mm3Z2NQtwOwWKPsQ60roV_pjwxH_DkoQIrP2vZ89YV/pub
Complexity: Hard
Pros: Off map artillery provides strong in direct fire without being vulnerable themselves + Infantry is powerful and scales well into the late game + Buildable Pak 40s.
Cons: Limited armor options and no heavy tanks + Munition hungry

Luftwaffe Doctrine

https://docs.google.com/document/d/e/2PACX-1vQJLQWIvRIsCZJW7DPM1VoXZ2FsVm71yIgxp2aoagbAJEp_SQGt3xddj3lTkvFZap0K5DDhBSWv4B7n/pub
Complexity: Medium
Pros: Fallschrimjager elite infantry + Numerous air strikes + Buildable Panthers
Cons: Expensive munition requirements + Expensive manpower due to high reinforcement costs

Iron Will Doctrine

https://docs.google.com/document/d/e/2PACX-1vQEO_F6I-7bTXMnOJGRpMGlZUvvYIHNjjx_pt3mkaGh1prM4iYYFXbemVaGmdUp1xu_B0JA0mFKrOEo/pub
Complexity: Expert
Pros: Powerful on the defense + Potent late game call ins like triple Tiger tanks
Cons: One of the most micro intensive doctrines + RNG forces adaptation + Awkward timings