A calculation engine of an apparatus in an example is employable for interactive simulation gaming to create an active learning environment on credit risk management for a learner. The calculation engine simulates one or more retail lending portfolios in a retail bank over a selectable period of time in the active learning environment for the learner. The calculation engine allows and/or requests the learner to decide, select, and/or choose one or more parameters for a strategy for credit policy and/or loan approval. The calculation engine employs the one or more parameters from the learner to calculate a financial outcome of the one or more retail lending portfolios in the retail bank over the selectable period of time that reflects the strategy for credit policy and/or loan approval by the learner in a corresponding run of the active learning environment on credit risk management for the learner.