Robotech Robolinks Variations
As they are easier to find than the Japanese releases, Robotech Robolinks sets are useful for observing variants.
The most obvious variants are the Blockman robot colours in Force 1X and Force 2X. These colours do not seem to follow any discernible order, nor be synchronised with colour of the parts. The Force 1X and Force 2X Blockman robots appear to be drawn from a pool of multi-coloured Blockman robots.
With the larger sets, there are light-type versus heavy-type variants. For example, you can find Force 31 with one yellow light-type Blockman robot and four silver heavy-type Blockman robots (blue chest decals), or you can find it with one yellow heavy-type Blockman robot (red chest decals) and four grey light-type Blockman robots. In this case, I suspect the silver Blockman robots were drawn on to fill a shortfall, as grey is definitely the correct colour for this set. I’m not sure if this level of variability extended to the Japanese Combination Warrior Blockman releases.
One of the larger variants is for Force 41. This set typically comes with two regular blue Blockman robots and four dark blue Blockman robots. However, it can also have four regular blue Blockman robots and two dark blue Blockman robots.
In contrast, Force 42 has a smaller variant. The red heavy-type Blockman robots included with this set can either have blue or black chest decals.
Force 50 has a variant in the colour of the Blockman robot limbs. It is an eight-Blockman robot set that normally includes two white heavy-type Blockman robots (red chest decals) with light blue arms, as shown in the photograph on the back of the box. However, you can sometimes find that these Force 50 Blockman robots have turquoise blue arms instead of light blue. I’m not sure whether this variation carries over to the Force 1X and Force 5X releases, which included this multi-coloured Blockman robot in their random colour pool. Complicating things further, in Japan this Blockman robot was included with A-12, and had regular blue arms instead of light blue arms!
Finally, a smaller source of variation is the numbers on different parts. Where there are duplicates of different parts, each will normally have different number stamped on them. For example, the four tank treads included with Force 42 are numbered 1 to 4. The smaller parts often continue the numbering of parts on the same sprue or otherwise of the same colour, and these numbers can differ across sets. You might want to be aware of these numbers if you are trying to fill in some incomplete sets using loose parts.