set_mandala_contract_tier_effect

set_mandala_contract_tier_effect = {
	#Consider county_opinion as a factor
	random_list = {
		30 = {
			save_scope_value_as = {
				name = mandala_task_contract_tier
				value = define:NTaskContract|LOW_TASK_CONTRACT_TIER
			}
		}
		10 = {
			save_scope_value_as = {
				name = mandala_task_contract_tier
				value = define:NTaskContract|MEDIUM_TASK_CONTRACT_TIER
			}

			modifier = {
				add = 10
				scope:target_province.county.county_opinion >= 10
			}
			modifier = {
				add = 10
				scope:target_province.county.county_opinion >= 20
			}
		}
		5 = {
			save_scope_value_as = {
				name = mandala_task_contract_tier
				value = define:NTaskContract|HIGH_TASK_CONTRACT_TIER
			}

			modifier = {
				add = 10
				scope:target_province.county.county_opinion >= 40
			}
			modifier = {
				add = 10
				scope:target_province.county.county_opinion >= 60
			}
			modifier = {
				add = 10
				scope:target_province.county.county_opinion >= 80
			}
			modifier = {
				add = 10
				scope:target_province.county.county_opinion >= 100
			}
		}
	}
}

As written in game/common/scripted_effects/tgp_mandala_scripted_effects.txt.