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Model size determines how many models can be in contact with one model 
There are 2 model size types in DO: regular and large
regular-size model is any model from human to horsemen and it can be surrounded by up to 4 regular-size models and up to ? 3 large-size models
large-size model is usually a monster like troll or giant scorpion and it can be surrounded by up to 8 regular-size models and up to ? 4 large-size models

This video demonstrates 1 large-size model vs 8 normal-size models contact 
1 large-size model contact vs 4 large-size models contact
1 normal-size model vs 3 large-size models contact

Testnotes

Unit1 > Unit2 attacking -  up to +4 models bonus
Unit1 > Unit2 defending - up to +2 models bonus

Unit1 = Unit2 attacking -  up to +2 models bonus

normal-size unit attack large-size model - 8 models in contact and if vice versa - 6-8 models in contact

There is a limit of maximum allowed models in contact which depends on such conditions as:

• both units size
• who charged (attacker)

charged arcs and in rear arc gives +3 models in contact more for attacker vs +2 models in ather arcs (front or flanks)

unit formation doesn't give models in contact bonus

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